diff --git a/app/controllers/admin/registrars_controller.rb b/app/controllers/admin/registrars_controller.rb
index 7aa5809d49..7ca79a4502 100644
--- a/app/controllers/admin/registrars_controller.rb
+++ b/app/controllers/admin/registrars_controller.rb
@@ -1,4 +1,6 @@
 require 'net/http'
+require 'securerandom'
+require 'stringio'
 
 module Admin
   class RegistrarsController < BaseController # rubocop:disable Metrics/ClassLength
@@ -13,8 +15,25 @@ class RegistrarsController < BaseController # rubocop:disable Metrics/ClassLengt
     def index
       registrars = filter_by_status
       @q = registrars.ransack(params[:q])
-      @registrars = @q.result(distinct: true).page(params[:page])
+      @registrars_scope = @q.result(distinct: true)
+      @registrars = @registrars_scope.page(params[:page])
       @registrars = @registrars.per(params[:results_per_page]) if paginate?
+
+      respond_to do |format|
+        format.html
+        format.csv do
+          export_scope = selected_export_scope(@registrars_scope)
+          send_data(
+            CsvSync::Exporter.call(
+              model_class: Registrar,
+              records: export_scope,
+              fields: csv_export_fields
+            ),
+            filename: "registrars-#{Time.zone.today}.csv",
+            type: 'text/csv'
+          )
+        end
+      end
     end
 
     def new
@@ -64,6 +83,65 @@ def destroy
       end
     end
 
+    def import
+      @csv_sync_fields = Registrar.csv_sync_default_import_fields
+      @selected_fields = @csv_sync_fields
+      @csv_sync_field_groups = csv_sync_field_groups
+    end
+
+    def import_preview
+      set_import_form_defaults
+      @result = empty_import_result
+
+      if params[:file].blank?
+        flash.now[:alert] = t('admin.registrars.import_preview.file_required')
+        return render :import
+      end
+
+      @result = CsvSync::Importer.preview(
+        model_class: Registrar,
+        file: params[:file],
+        fields: @selected_fields
+      )
+      @row_results = @result.row_results
+      @import_token = cache_import_file(params[:file])
+      render :import_preview
+    rescue StandardError => e
+      @result = empty_import_result(errors: 1, row_results: [{ line_number: '-', action: :error, key_values: {}, changes: [], error: e.message }])
+      flash.now[:alert] = t('admin.registrars.import_preview.failed')
+      render :import
+    end
+
+    def import_apply
+      set_import_form_defaults
+      @result = empty_import_result
+      file = file_from_apply_params
+
+      if file.blank?
+        flash[:alert] = t('admin.registrars.import_apply.file_not_found')
+        return redirect_to import_admin_registrars_path
+      end
+
+      @result = CsvSync::Importer.apply(
+        model_class: Registrar,
+        file: file,
+        fields: @selected_fields
+      )
+      clear_cached_import_file(params[:import_token])
+
+      flash[:notice] = t(
+        'admin.registrars.import_apply.completed',
+        created: @result.created,
+        updated: @result.updated,
+        unchanged: @result.unchanged,
+        errors: @result.errors
+      )
+      redirect_to admin_registrars_path
+    rescue StandardError => e
+      flash[:alert] = "#{t('admin.registrars.import_apply.failed')}: #{e.message}"
+      redirect_to import_admin_registrars_path
+    end
+
     private
 
     def filter_by_status
@@ -134,5 +212,65 @@ def allowed_method(records_param)
       allowed_methods = %w[api_users white_ips]
       records_param if allowed_methods.include?(records_param)
     end
+
+    def csv_export_fields
+      params.fetch(:csv_fields, []).reject(&:blank?)
+    end
+
+    def selected_export_scope(scope)
+      return scope unless params[:export_selected].present?
+
+      selected_ids = params.fetch(:registrar_ids, []).reject(&:blank?)
+      return scope.none if selected_ids.empty?
+
+      scope.where(id: selected_ids)
+    end
+
+    def set_import_form_defaults
+      @csv_sync_fields = Registrar.csv_sync_default_import_fields
+      @selected_fields = params.fetch(:fields, []).reject(&:blank?)
+      @selected_fields = @csv_sync_fields if @selected_fields.empty?
+      @csv_sync_field_groups = csv_sync_field_groups
+    end
+
+    def csv_sync_field_groups
+      { t('admin.csv_sync.field_checkboxes.default_group') => Registrar.csv_sync_default_import_fields }
+    end
+
+    def empty_import_result(errors: 0, row_results: [])
+      CsvSync::Importer::Result.new(
+        created: 0,
+        updated: 0,
+        unchanged: 0,
+        errors: errors,
+        row_results: row_results
+      )
+    end
+
+    def cache_import_file(file)
+      token = SecureRandom.uuid
+      io = file.respond_to?(:tempfile) ? file.tempfile : file
+      io.rewind if io.respond_to?(:rewind)
+      csv_payload = io.read
+      session[:registrars_csv_imports] ||= {}
+      session[:registrars_csv_imports][token] = csv_payload
+      token
+    end
+
+    def file_from_apply_params
+      return params[:file] if params[:file].present?
+      return nil if params[:import_token].blank?
+
+      csv_payload = session.fetch(:registrars_csv_imports, {})[params[:import_token]]
+      return nil if csv_payload.blank?
+
+      StringIO.new(csv_payload)
+    end
+
+    def clear_cached_import_file(token)
+      return if token.blank?
+
+      session[:registrars_csv_imports]&.delete(token)
+    end
   end
 end
diff --git a/app/models/concerns/csv_sync/model_config.rb b/app/models/concerns/csv_sync/model_config.rb
new file mode 100644
index 0000000000..4b3a0759fc
--- /dev/null
+++ b/app/models/concerns/csv_sync/model_config.rb
@@ -0,0 +1,104 @@
+module CsvSync::ModelConfig
+  extend ActiveSupport::Concern
+
+  BOOLEAN_TRUE_VALUES = %w[1 true t yes y on].freeze
+  BOOLEAN_FALSE_VALUES = %w[0 false f no n off].freeze
+
+  class_methods do
+    def csv_sync_field_definitions
+      const_get(:FIELD_DEFINITIONS)
+    end
+
+    def csv_sync_fields
+      csv_sync_field_definitions.keys
+    end
+
+    def csv_sync_key_fields
+      csv_sync_field_definitions.filter_map { |field, config| field if config[:key] }
+    end
+
+    def csv_sync_default_export_fields
+      csv_sync_field_definitions.filter_map { |field, config| field if config[:default_export] }
+    end
+
+    def csv_sync_default_import_fields
+      csv_sync_field_definitions.filter_map { |field, config| field if config[:default_import] }
+    end
+
+    def csv_sync_type_for(field)
+      csv_sync_field_definitions.fetch(field.to_sym).fetch(:type)
+    end
+
+    def csv_sync_import_value(field, raw_value)
+      csv_sync_deserialize(raw_value, type: csv_sync_type_for(field))
+    end
+
+    def csv_sync_export_value(field, value)
+      csv_sync_serialize(value, type: csv_sync_type_for(field))
+    end
+
+    private
+
+    def csv_sync_serialize(value, type:)
+      return nil if value.nil?
+
+      case type
+      when :boolean
+        value ? 'true' : 'false'
+      when :decimal
+        value.to_s
+      when :datetime
+        value.respond_to?(:iso8601) ? value.iso8601 : value.to_s
+      when :json
+        value.to_json
+      else
+        value.to_s
+      end
+    end
+
+    def csv_sync_deserialize(raw_value, type:)
+      value = raw_value.is_a?(String) ? raw_value.strip : raw_value
+      return nil if value.blank?
+
+      case type
+      when :boolean
+        parse_csv_sync_boolean(value)
+      when :decimal
+        BigDecimal(value.to_s)
+      when :datetime
+        Time.zone.parse(value.to_s)
+      when :json
+        parse_csv_sync_json(value)
+      else
+        value
+      end
+    end
+
+    def parse_csv_sync_boolean(value)
+      normalized = value.to_s.strip.downcase
+      return true if BOOLEAN_TRUE_VALUES.include?(normalized)
+      return false if BOOLEAN_FALSE_VALUES.include?(normalized)
+
+      raise ArgumentError, "Invalid boolean value: #{value.inspect}"
+    end
+
+    def parse_csv_sync_json(value)
+      case value
+      when Hash
+        value
+      else
+        JSON.parse(value.to_s)
+      end
+    rescue JSON::ParserError => e
+      raise ArgumentError, "Invalid JSON value: #{e.message}"
+    end
+  end
+
+  def csv_sync_export_value(field)
+    self.class.csv_sync_export_value(field, public_send(field))
+  end
+
+  def csv_sync_import_value(field, raw_value)
+    self.class.csv_sync_import_value(field, raw_value)
+  end
+end
diff --git a/app/models/concerns/registrar/csv_sync.rb b/app/models/concerns/registrar/csv_sync.rb
new file mode 100644
index 0000000000..232b5406c7
--- /dev/null
+++ b/app/models/concerns/registrar/csv_sync.rb
@@ -0,0 +1,38 @@
+module Registrar::CsvSync
+  extend ActiveSupport::Concern
+  include CsvSync::ModelConfig
+
+  FIELD_DEFINITIONS = {
+    code: {
+      key: true,
+      default_export: true,
+      default_import: false,
+      type: :string,
+    },
+    name: { default_export: true, default_import: true, type: :string },
+    reg_no: { default_export: true, default_import: true, type: :string },
+    email: { default_export: true, default_import: true, type: :string },
+    billing_email: { default_export: true, default_import: true, type: :string },
+    phone: { default_export: true, default_import: true, type: :string },
+    website: { default_export: true, default_import: true, type: :string },
+    language: { default_export: true, default_import: true, type: :string },
+    test_registrar: { default_export: true, default_import: false, type: :boolean },
+    address_street: { default_export: true, default_import: true, type: :string },
+    address_zip: { default_export: true, default_import: true, type: :string },
+    address_city: { default_export: true, default_import: true, type: :string },
+    address_state: { default_export: true, default_import: true, type: :string },
+    address_country_code: { default_export: true, default_import: true, type: :string },
+    vat_no: { default_export: true, default_import: true, type: :string },
+    vat_rate: { default_export: true, default_import: true, type: :decimal },
+    iban: { default_export: true, default_import: true, type: :string },
+    accounting_customer_code: { default_export: true, default_import: false, type: :string },
+    reference_no: { default_export: true, default_import: false, type: :string },
+    legaldoc_optout: { default_export: true, default_import: true, type: :boolean },
+    legaldoc_optout_comment: { default_export: true, default_import: true, type: :string },
+    accept_pdf_invoices: { default_export: true, default_import: true, type: :boolean },
+    settings: { default_export: true, default_import: true, type: :json },
+    accreditation_date: { default_export: true, default_import: false, type: :datetime },
+    accreditation_expire_date: { default_export: true, default_import: false, type: :datetime },
+  }.freeze
+
+end
diff --git a/app/models/registrar.rb b/app/models/registrar.rb
index afe304242f..7c7ad26777 100644
--- a/app/models/registrar.rb
+++ b/app/models/registrar.rb
@@ -1,6 +1,7 @@
 class Registrar < ApplicationRecord # rubocop:disable Metrics/ClassLength
   include Versions # version/registrar_version.rb
   include Registrar::BookKeeping
+  include Registrar::CsvSync
   include EmailVerifable
   include Registrar::LegalDoc
 
diff --git a/app/services/csv_sync/exporter.rb b/app/services/csv_sync/exporter.rb
new file mode 100644
index 0000000000..ec269a07e7
--- /dev/null
+++ b/app/services/csv_sync/exporter.rb
@@ -0,0 +1,38 @@
+require 'csv'
+
+class CsvSync::Exporter
+  def self.call(model_class:, records:, fields: nil)
+    new(model_class: model_class, records: records, fields: fields).to_csv
+  end
+
+  def initialize(model_class:, records:, fields: nil)
+    @model_class = model_class
+    @records = records
+    @fields = normalize_fields(fields)
+  end
+
+  def to_csv
+    CSV.generate do |csv|
+      csv << headers
+      records.find_each do |record|
+        csv << fields.map { |field| model_class.csv_sync_export_value(field, record.public_send(field)) }
+      end
+    end
+  end
+
+  private
+
+  attr_reader :model_class, :records, :fields
+
+  def normalize_fields(fields)
+    allowed_fields = model_class.csv_sync_fields
+    selected_fields = Array(fields).map(&:to_sym).select { |field| allowed_fields.include?(field) }
+    selected_fields = model_class.csv_sync_default_export_fields if selected_fields.empty?
+
+    (model_class.csv_sync_key_fields + selected_fields).uniq
+  end
+
+  def headers
+    fields.map(&:to_s)
+  end
+end
diff --git a/app/services/csv_sync/importer.rb b/app/services/csv_sync/importer.rb
new file mode 100644
index 0000000000..5b4777fccd
--- /dev/null
+++ b/app/services/csv_sync/importer.rb
@@ -0,0 +1,226 @@
+require 'csv'
+
+class CsvSync::Importer
+  Result = Struct.new(:created, :updated, :unchanged, :errors, :row_results, keyword_init: true) do
+    def total
+      created + updated + unchanged + errors
+    end
+  end
+
+  def self.preview(model_class:, file:, fields: nil)
+    new(model_class: model_class, file: file, fields: fields).preview
+  end
+
+  def self.apply(model_class:, file:, fields: nil)
+    new(model_class: model_class, file: file, fields: fields).apply
+  end
+
+  def initialize(model_class:, file:, fields: nil)
+    @model_class = model_class
+    @file = file
+    @fields = normalize_fields(fields)
+  end
+
+  def preview
+    process_rows(persist: false)
+  end
+
+  def apply
+    process_rows(persist: true)
+  end
+
+  private
+
+  attr_reader :model_class, :file, :fields
+
+  def process_rows(persist:)
+    rows = parse_rows
+    ensure_key_headers!(rows.headers)
+
+    row_results = rows.map.with_index(2) do |row, line_number|
+      process_row(row, line_number: line_number, persist: persist)
+    rescue StandardError => e
+      build_error_result(line_number: line_number, error: e.message)
+    end
+
+    summarize(row_results)
+  end
+
+  def process_row(row, line_number:, persist:)
+    key_values = parse_key_values(row)
+    record = find_record(key_values)
+    attrs = parse_import_attrs(row)
+
+    if record
+      diff_attrs = changed_attrs(record, attrs)
+      return build_row_result(line_number: line_number, action: :unchanged) if diff_attrs.empty?
+
+      if persist
+        apply_update!(record, diff_attrs)
+      else
+        record.assign_attributes(diff_attrs)
+        raise ActiveRecord::RecordInvalid, record unless record.valid?
+      end
+
+      build_row_result(
+        line_number: line_number,
+        action: :updated,
+        key_values: key_values,
+        changes: diff_attrs.keys
+      )
+    else
+      create_attrs = key_values.merge(attrs)
+
+      if persist
+        apply_create!(create_attrs)
+      else
+        preview_record = model_class.new(create_attrs)
+        raise ActiveRecord::RecordInvalid, preview_record unless preview_record.valid?
+      end
+
+      build_row_result(line_number: line_number, action: :created, key_values: key_values)
+    end
+  rescue ActiveRecord::RecordInvalid => e
+    build_error_result(
+      line_number: line_number,
+      key_values: key_values,
+      error: e.record.errors.full_messages.to_sentence
+    )
+  rescue ArgumentError, TypeError => e
+    build_error_result(line_number: line_number, key_values: key_values, error: e.message)
+  end
+
+  def parse_rows
+    io = file.respond_to?(:tempfile) ? file.tempfile : file
+    io.rewind if io.respond_to?(:rewind)
+    content = io.read
+    CSV.parse(content, headers: true, col_sep: detect_col_sep(content))
+  end
+
+  def detect_col_sep(content)
+    first_line = content.to_s.each_line.first.to_s
+    comma_count = first_line.count(',')
+    semicolon_count = first_line.count(';')
+    semicolon_count > comma_count ? ';' : ','
+  end
+
+  def parse_key_values(row)
+    model_class.csv_sync_key_fields.each_with_object({}) do |field, acc|
+      header = field.to_s
+      raw_value = row[header]
+      if raw_value.blank?
+        raise ArgumentError, "Missing #{header} value"
+      end
+
+      acc[field] = model_class.csv_sync_import_value(field, raw_value)
+    end
+  end
+
+  def parse_import_attrs(row)
+    fields.each_with_object({}) do |field, acc|
+      next if model_class.csv_sync_key_fields.include?(field)
+
+      header = field.to_s
+      next unless row.headers.include?(header)
+
+      acc[field] = model_class.csv_sync_import_value(field, row[header])
+    end
+  end
+
+  def ensure_key_headers!(headers)
+    missing_headers = model_class.csv_sync_key_fields.map(&:to_s) - headers
+    return if missing_headers.empty?
+
+    raise ArgumentError, "Missing required CSV headers: #{missing_headers.join(', ')}"
+  end
+
+  def normalize_fields(fields)
+    allowed_fields = model_class.csv_sync_fields
+    selected_fields = Array(fields).map(&:to_sym).select { |field| allowed_fields.include?(field) }
+    selected_fields = model_class.csv_sync_default_import_fields if selected_fields.empty?
+
+    (model_class.csv_sync_key_fields + selected_fields).uniq
+  end
+
+  def find_record(key_values)
+    scope = model_class.all
+
+    key_values.each do |field, value|
+      if value.is_a?(String)
+        column_name = model_class.connection.quote_column_name(field)
+        scope = scope.where("UPPER(#{column_name}) = ?", value.upcase)
+      else
+        scope = scope.where(field => value)
+      end
+    end
+
+    scope.first
+  end
+
+  def changed_attrs(record, attrs)
+    attrs.each_with_object({}) do |(field, value), changes|
+      changes[field] = value if record.public_send(field) != value
+    end
+  end
+
+  def apply_create!(attrs)
+    if model_class.respond_to?(:csv_sync_create_record)
+      model_class.csv_sync_create_record(attrs)
+      return
+    end
+
+    if model_class.name == 'Registrar'
+      create_registrar!(attrs)
+      return
+    end
+
+    model_class.create!(attrs)
+  end
+
+  def apply_update!(record, attrs)
+    if model_class.respond_to?(:csv_sync_update_record)
+      model_class.csv_sync_update_record(record, attrs)
+      return
+    end
+
+    record.update!(attrs)
+  end
+
+  def create_registrar!(attrs)
+    registrar = model_class.new(attrs)
+    registrar.reference_no ||= ::Billing::ReferenceNo.generate(owner: registrar.name)
+
+    registrar.transaction do
+      registrar.save!
+      registrar.accounts.create!(account_type: Account::CASH, currency: 'EUR')
+    end
+  end
+
+  def summarize(row_results)
+    Result.new(
+      created: row_results.count { |result| result[:action] == :created },
+      updated: row_results.count { |result| result[:action] == :updated },
+      unchanged: row_results.count { |result| result[:action] == :unchanged },
+      errors: row_results.count { |result| result[:action] == :error },
+      row_results: row_results
+    )
+  end
+
+  def build_row_result(line_number:, action:, key_values: {}, changes: [])
+    {
+      line_number: line_number,
+      action: action,
+      key_values: key_values,
+      changes: changes,
+    }
+  end
+
+  def build_error_result(line_number:, key_values: {}, error:)
+    build_row_result(
+      line_number: line_number,
+      action: :error,
+      key_values: key_values,
+      changes: []
+    ).merge(error: error)
+  end
+end
diff --git a/app/views/admin/csv_sync/_export_actions.html.erb b/app/views/admin/csv_sync/_export_actions.html.erb
new file mode 100644
index 0000000000..6fb89c386d
--- /dev/null
+++ b/app/views/admin/csv_sync/_export_actions.html.erb
@@ -0,0 +1,17 @@
+<% export_label = local_assigns.fetch(:export_label, t('admin.csv_sync.export_actions.export_btn')) %>
+<% reset_label = local_assigns.fetch(:reset_label, t('admin.csv_sync.export_actions.reset_btn')) %>
+
+<div class="panel panel-default">
+  <div class="panel-heading"><%= t('admin.csv_sync.export_actions.panel_title') %></div>
+  <div class="panel-body">
+    <div class="row">
+      <div class="col-md-12">
+        <%= hidden_field_tag export_selected_param, '1' %>
+        <%= submit_tag export_label, class: 'btn btn-default' %>
+        <% if local_assigns[:reset_url].present? %>
+          <%= link_to reset_label, reset_url, class: 'btn btn-default' %>
+        <% end %>
+      </div>
+    </div>
+  </div>
+</div>
diff --git a/app/views/admin/csv_sync/_field_checkboxes.html.erb b/app/views/admin/csv_sync/_field_checkboxes.html.erb
new file mode 100644
index 0000000000..8e632ac9b9
--- /dev/null
+++ b/app/views/admin/csv_sync/_field_checkboxes.html.erb
@@ -0,0 +1,33 @@
+<% panel_title = local_assigns.fetch(:panel_title, t('admin.csv_sync.field_checkboxes.panel_title')) %>
+<% field_groups = local_assigns[:field_groups].presence || { t('admin.csv_sync.field_checkboxes.default_group') => fields } %>
+<% selected_set = Array(selected_fields).map(&:to_s) %>
+<% input_name = local_assigns.fetch(:input_name, 'fields[]') %>
+
+<div class="panel panel-default">
+  <div class="panel-heading"><%= panel_title %></div>
+  <div class="panel-body">
+    <% field_groups.each do |group_name, group_fields| %>
+      <div class="row">
+        <div class="col-md-12">
+          <h5><%= group_name %></h5>
+        </div>
+      </div>
+      <div class="row">
+        <% Array(group_fields).each do |field| %>
+          <% field_name = field.to_s %>
+          <div class="col-md-3">
+            <div class="checkbox">
+              <label>
+                <%= check_box_tag input_name, field_name, selected_set.include?(field_name), id: "#{input_name.to_s.parameterize(separator: '_')}_#{field_name}" %>
+                <%= t("activerecord.attributes.#{model_name}.#{field_name}", default: field_name.humanize) %>
+              </label>
+            </div>
+          </div>
+        <% end %>
+      </div>
+      <% unless group_name == field_groups.keys.last %>
+        <hr>
+      <% end %>
+    <% end %>
+  </div>
+</div>
diff --git a/app/views/admin/csv_sync/_import_form.html.erb b/app/views/admin/csv_sync/_import_form.html.erb
new file mode 100644
index 0000000000..e524148a71
--- /dev/null
+++ b/app/views/admin/csv_sync/_import_form.html.erb
@@ -0,0 +1,45 @@
+<% form_method = local_assigns.fetch(:method, :post) %>
+<% submit_label = local_assigns.fetch(:submit_label, t('admin.csv_sync.import_form.submit_btn')) %>
+<% file_param = local_assigns.fetch(:file_param, :file) %>
+<% file_label = local_assigns.fetch(:file_label, t('admin.csv_sync.import_form.file_label')) %>
+<% instructions = local_assigns.fetch(:instructions, t('admin.csv_sync.import_form.instructions')) %>
+<% fields_open = local_assigns.fetch(:fields_open, false) %>
+
+<%= form_tag url, method: form_method, multipart: true do %>
+  <p><%= instructions %></p>
+
+  <div class="form-group">
+    <%= label_tag file_param, file_label %>
+    <%= file_field_tag file_param, required: true, accept: 'text/csv' %>
+  </div>
+
+  <div class="row">
+    <div class="col-md-12">
+      <a
+        role="button"
+        data-toggle="collapse"
+        href="#csv-import-fields"
+        aria-expanded="<%= fields_open %>"
+        aria-controls="csv-import-fields">
+        <%= t('admin.csv_sync.import_form.toggle_fields_btn') %>
+      </a>
+    </div>
+  </div>
+
+  <div id="csv-import-fields" class="collapse <%= 'in' if fields_open %>">
+    <%= render 'admin/csv_sync/field_checkboxes',
+        fields: fields,
+        selected_fields: selected_fields,
+        model_name: model_name,
+        field_groups: local_assigns[:field_groups],
+        input_name: local_assigns.fetch(:input_name, 'fields[]'),
+        panel_title: local_assigns.fetch(:panel_title, t('admin.csv_sync.import_form.fields_panel_title')) %>
+  </div>
+
+  <div class="form-group text-right">
+    <%= submit_tag submit_label, class: 'btn btn-primary' %>
+    <% if local_assigns[:cancel_url].present? %>
+      <%= link_to t('admin.csv_sync.import_form.cancel_btn'), cancel_url, class: 'btn btn-default' %>
+    <% end %>
+  </div>
+<% end %>
diff --git a/app/views/admin/csv_sync/_preview_summary.html.erb b/app/views/admin/csv_sync/_preview_summary.html.erb
new file mode 100644
index 0000000000..e9613b4fde
--- /dev/null
+++ b/app/views/admin/csv_sync/_preview_summary.html.erb
@@ -0,0 +1,23 @@
+<div class="panel panel-default">
+  <div class="panel-heading"><%= t('admin.csv_sync.preview_summary.panel_title') %></div>
+  <div class="panel-body">
+    <div class="row">
+      <div class="col-sm-3">
+        <strong><%= t('admin.csv_sync.preview_summary.created') %>:</strong>
+        <%= result.created %>
+      </div>
+      <div class="col-sm-3">
+        <strong><%= t('admin.csv_sync.preview_summary.updated') %>:</strong>
+        <%= result.updated %>
+      </div>
+      <div class="col-sm-3">
+        <strong><%= t('admin.csv_sync.preview_summary.unchanged') %>:</strong>
+        <%= result.unchanged %>
+      </div>
+      <div class="col-sm-3">
+        <strong><%= t('admin.csv_sync.preview_summary.errors') %>:</strong>
+        <span class="<%= result.errors.positive? ? 'text-danger' : 'text-success' %>"><%= result.errors %></span>
+      </div>
+    </div>
+  </div>
+</div>
diff --git a/app/views/admin/csv_sync/_preview_table.html.erb b/app/views/admin/csv_sync/_preview_table.html.erb
new file mode 100644
index 0000000000..ba4e70abcf
--- /dev/null
+++ b/app/views/admin/csv_sync/_preview_table.html.erb
@@ -0,0 +1,37 @@
+<div class="table-responsive">
+  <table class="table table-hover table-bordered table-condensed">
+    <thead>
+      <tr>
+        <th><%= t('admin.csv_sync.preview_table.line') %></th>
+        <th><%= t('admin.csv_sync.preview_table.key') %></th>
+        <th><%= t('admin.csv_sync.preview_table.action') %></th>
+        <th><%= t('admin.csv_sync.preview_table.changes') %></th>
+        <th><%= t('admin.csv_sync.preview_table.error') %></th>
+      </tr>
+    </thead>
+    <tbody>
+      <% row_results.each do |row| %>
+        <% action = row[:action].to_s %>
+        <% action_class = action == 'error' ? 'text-danger' : (action == 'unchanged' ? '' : 'text-success') %>
+        <tr>
+          <td><%= row[:line_number] %></td>
+          <td>
+            <% key_fields.each do |field| %>
+              <% value = row.fetch(:key_values, {})[field.to_sym] || row.fetch(:key_values, {})[field.to_s] %>
+              <%= "#{field}: #{value}" %><br>
+            <% end %>
+          </td>
+          <td class="<%= action_class %>"><%= t("admin.csv_sync.actions.#{action}", default: action.humanize) %></td>
+          <td>
+            <% if row[:changes].present? %>
+              <%= row[:changes].map { |field| t("activerecord.attributes.#{model_name}.#{field}", default: field.to_s.humanize) }.join(', ') %>
+            <% else %>
+              <span class="text-muted">-</span>
+            <% end %>
+          </td>
+          <td class="text-danger"><%= row[:error] %></td>
+        </tr>
+      <% end %>
+    </tbody>
+  </table>
+</div>
diff --git a/app/views/admin/registrars/_search_form.html.erb b/app/views/admin/registrars/_search_form.html.erb
index 4cfc447b2f..4b011c65ec 100644
--- a/app/views/admin/registrars/_search_form.html.erb
+++ b/app/views/admin/registrars/_search_form.html.erb
@@ -16,7 +16,7 @@
                     </div>
                 </div>
                 <div class="col-md-3 text-right" style="padding-top: 25px;float: right;padding-right: 15px;">
-                    <button class="btn btn-default search">
+                    <button type="submit" class="btn btn-default search">
                         &nbsp;
                         <span class="glyphicon glyphicon-search"></span>
                         &nbsp;
diff --git a/app/views/admin/registrars/import.html.erb b/app/views/admin/registrars/import.html.erb
new file mode 100644
index 0000000000..337a7f25d2
--- /dev/null
+++ b/app/views/admin/registrars/import.html.erb
@@ -0,0 +1,25 @@
+<% fields = Array(@csv_sync_fields || @fields) %>
+<% selected_fields = Array(@selected_fields).presence || fields %>
+<% field_groups = @csv_sync_field_groups || @field_groups %>
+
+<ol class="breadcrumb">
+  <li><%= link_to t('admin.registrars.index.header'), admin_registrars_path %></li>
+  <li class="active"><%= t('.header') %></li>
+</ol>
+
+<div class="page-header">
+  <h1><%= t('.header') %></h1>
+</div>
+
+<div class="panel panel-default">
+  <div class="panel-heading"><%= t('.panel_title') %></div>
+  <div class="panel-body">
+    <%= render 'admin/csv_sync/import_form',
+        url: import_preview_admin_registrars_path,
+        fields: fields,
+        selected_fields: selected_fields,
+        model_name: :registrar,
+        field_groups: field_groups,
+        cancel_url: admin_registrars_path %>
+  </div>
+</div>
diff --git a/app/views/admin/registrars/import_preview.html.erb b/app/views/admin/registrars/import_preview.html.erb
new file mode 100644
index 0000000000..76332cf3e5
--- /dev/null
+++ b/app/views/admin/registrars/import_preview.html.erb
@@ -0,0 +1,37 @@
+<% key_fields = Array(@key_fields).presence || %i[code] %>
+<% selected_fields = Array(@selected_fields) %>
+<% row_results = @result&.row_results || @row_results || [] %>
+
+<ol class="breadcrumb">
+  <li><%= link_to t('admin.registrars.index.header'), admin_registrars_path %></li>
+  <li><%= link_to t('admin.registrars.import.header'), import_admin_registrars_path %></li>
+  <li class="active"><%= t('.header') %></li>
+</ol>
+
+<div class="page-header">
+  <h1><%= t('.header') %></h1>
+</div>
+
+<%= render 'admin/csv_sync/preview_summary', result: @result %>
+
+<div class="panel panel-default">
+  <div class="panel-heading"><%= t('.changes_panel_title') %></div>
+  <div class="panel-body">
+    <%= render 'admin/csv_sync/preview_table',
+        row_results: row_results,
+        key_fields: key_fields,
+        model_name: :registrar %>
+  </div>
+  <div class="panel-footer text-right">
+    <%= form_tag import_apply_admin_registrars_path, method: :post, multipart: true, style: 'display: inline-block;' do %>
+      <% selected_fields.each do |field| %>
+        <%= hidden_field_tag 'fields[]', field %>
+      <% end %>
+      <% if @import_token.present? %>
+        <%= hidden_field_tag :import_token, @import_token %>
+      <% end %>
+      <%= submit_tag t('.confirm_btn'), class: 'btn btn-primary' %>
+    <% end %>
+    <%= link_to t('.back_btn'), import_admin_registrars_path, class: 'btn btn-default' %>
+  </div>
+</div>
diff --git a/app/views/admin/registrars/index.html.erb b/app/views/admin/registrars/index.html.erb
index a19ccdfc82..ac2b0ab074 100644
--- a/app/views/admin/registrars/index.html.erb
+++ b/app/views/admin/registrars/index.html.erb
@@ -1,10 +1,11 @@
 <div class="page-header">
     <div class="row">
-        <div class="col-sm-10">
+        <div class="col-sm-8">
             <h1><%= t '.header' %></h1>
         </div>
 
-        <div class="col-sm-2 text-right">
+        <div class="col-sm-4 text-right">
+            <%= link_to t('.import_btn'), import_admin_registrars_path, class: 'btn btn-default' %>
             <%= link_to t('.new_btn'), new_admin_registrar_path, class: 'btn btn-primary' %>
         </div>
     </div>
@@ -12,12 +13,54 @@
 
 <%= render 'search_form', search: @search %>
 
+<hr/>
+
+<%= form_tag admin_registrars_path(format: :csv), method: :get, class: 'form-horizontal', autocomplete: 'off' do %>
+    <% selected_csv_fields = params[:csv_fields].presence || Registrar.csv_sync_default_export_fields.map(&:to_s) %>
+    <% csv_fields_open = params[:csv_fields].present? %>
+    <% params.fetch(:q, {}).to_unsafe_h.each do |key, value| %>
+        <%= hidden_field_tag "q[#{key}]", value %>
+    <% end %>
+    <%= hidden_field_tag :status, params[:status] if params[:status].present? %>
+    <%= hidden_field_tag :results_per_page, params[:results_per_page] if params[:results_per_page].present? %>
+
+    <div class="row">
+      <div class="col-md-12">
+        <a
+           role="button"
+           data-toggle="collapse"
+           href="#registrar-csv-fields"
+           aria-expanded="<%= csv_fields_open %>"
+           aria-controls="registrar-csv-fields">
+          <%= t('.toggle_csv_fields_btn') %>
+        </a>
+      </div>
+    </div>
+
+    <div id="registrar-csv-fields" class="collapse <%= 'in' if csv_fields_open %>">
+      <%= render 'admin/csv_sync/field_checkboxes',
+                 fields: Registrar.csv_sync_default_export_fields,
+                 selected_fields: selected_csv_fields,
+                 model_name: 'registrar',
+                 panel_title: t('.csv_fields_label'),
+                 input_name: 'csv_fields[]' %>
+    </div>
+
+    <%= render 'admin/csv_sync/export_actions',
+               export_url: admin_registrars_path(format: :csv, params: params.permit!.to_h.except('controller', 'action', 'format', 'registrar_ids', 'export_selected')),
+               reset_url: admin_registrars_path,
+               export_selected_param: :export_selected,
+               export_label: t('.download_btn') %>
+
 <div class="row">
     <div class="col-md-12">
         <div class="table-responsive">
             <table class="table table-hover table-bordered table-condensed">
                 <thead>
                 <tr>
+                    <th class="col-xs-1 text-center">
+                        <%= check_box_tag :check_all %>
+                    </th>
                     <th class="col-xs-4">
                         <%= sort_link(@q, 'name') %>
                     </th>
@@ -42,6 +85,9 @@
                 <tbody>
                 <% @registrars.each do |x| %>
                     <tr>
+                        <td class="text-center">
+                            <%= check_box_tag 'registrar_ids[]', x.id, false, id: "registrar_ids_#{x.id}" %>
+                        </td>
                         <td>
                             <%= link_to(x, [:admin, x]) %>
                         </td>
@@ -76,6 +122,7 @@
         </div>
     </div>
 </div>
+<% end %>
 <div class="row">
     <div class="col-md-6">
         <%= paginate @registrars %>
@@ -86,3 +133,17 @@
         </div>
     </div>
 </div>
+
+<script>
+(function() {
+  const checkAll = document.getElementById('check_all');
+  if (!checkAll) return;
+
+  checkAll.addEventListener('click', () => {
+    const checkboxes = document.querySelectorAll('[id^="registrar_ids_"]');
+    for (let i = 0; i < checkboxes.length; i++) {
+      checkboxes[i].checked = checkAll.checked;
+    }
+  });
+})();
+</script>
diff --git a/config/locales/admin/csv_sync.en.yml b/config/locales/admin/csv_sync.en.yml
new file mode 100644
index 0000000000..ce8960c879
--- /dev/null
+++ b/config/locales/admin/csv_sync.en.yml
@@ -0,0 +1,34 @@
+en:
+  admin:
+    csv_sync:
+      actions:
+        created: Created
+        updated: Updated
+        unchanged: Unchanged
+        error: Error
+      field_checkboxes:
+        panel_title: CSV fields
+        default_group: Fields
+      import_form:
+        instructions: Upload a CSV file and choose which fields to apply.
+        file_label: CSV file
+        submit_btn: Preview import
+        cancel_btn: Cancel
+        fields_panel_title: Fields to apply
+      preview_summary:
+        panel_title: Import preview summary
+        created: Created
+        updated: Updated
+        unchanged: Unchanged
+        errors: Errors
+      preview_table:
+        line: Row
+        key: Key
+        action: Action
+        changes: Changed fields
+        error: Error details
+      export_actions:
+        panel_title: CSV export
+        export_btn: Export CSV
+        export_selected_btn: Export selected
+        reset_btn: Reset
diff --git a/config/locales/admin/registrars.en.yml b/config/locales/admin/registrars.en.yml
index 0550650586..fcf06c93da 100644
--- a/config/locales/admin/registrars.en.yml
+++ b/config/locales/admin/registrars.en.yml
@@ -1,9 +1,48 @@
 en:
   admin:
+    csv_sync:
+      actions:
+        created: Created
+        updated: Updated
+        unchanged: Unchanged
+        error: Error
+      field_checkboxes:
+        panel_title: Fields
+        default_group: Fields
+      import_form:
+        submit_btn: Preview import
+        file_label: CSV file
+        instructions: Upload a CSV file and choose fields to import.
+        fields_panel_title: Fields to import
+        toggle_fields_btn: Show/Hide import fields
+        cancel_btn: Cancel
+      preview_summary:
+        panel_title: Import summary
+        created: Created
+        updated: Updated
+        unchanged: Unchanged
+        errors: Errors
+      preview_table:
+        line: Line
+        key: Key
+        action: Action
+        changes: Changed fields
+        error: Error
+      export_actions:
+        panel_title: CSV export
+        export_btn: Export CSV
+        export_selected_btn: Export selected
+        reset_btn: Reset
+
     registrars:
       index:
         header: Registrars
         new_btn: New registrar
+        import_btn: Import CSV
+        download_btn: Export CSV
+        export_selected_btn: Export selected
+        toggle_csv_fields_btn: Show/Hide CSV fields
+        csv_fields_label: CSV fields
         set_test_btn: Set Accreditation
         remove_test_btn: Remove Accreditation
 
@@ -47,6 +86,23 @@ en:
       edit:
         header: Edit registrar
 
+      import:
+        header: Import registrars from CSV
+        panel_title: CSV import
+
+      import_preview:
+        header: Import preview
+        changes_panel_title: Row changes
+        confirm_btn: Apply import
+        back_btn: Back
+        file_required: Please select a CSV file.
+        failed: Failed to generate import preview
+
+      import_apply:
+        completed: "CSV import completed: %{created} created, %{updated} updated, %{unchanged} unchanged, %{errors} failed"
+        file_not_found: Import file was not found. Please upload the CSV again.
+        failed: Failed to apply import
+
       create:
         created: Registrar has been successfully created
 
@@ -83,5 +139,4 @@ en:
           header: Preferences
 
       search_form:
-        download_btn: Download CSV
         reset_btn: Reset
diff --git a/config/routes.rb b/config/routes.rb
index 7bb2e7c963..95546b511a 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -342,6 +342,9 @@
       resources :white_ips
 
       collection do
+        get 'import'
+        post 'import_preview'
+        post 'import_apply'
         post 'set_test_date_to_api_user', to: 'api_users#set_test_date_to_api_user', as: 'set_test_date_to_api_user'
         post 'remove_test_date_to_api_user', to: 'api_users#remove_test_date_to_api_user', as: 'remove_test_date_to_api_user'
       end
diff --git a/test/fixtures/files/registrars/export_filtered.csv b/test/fixtures/files/registrars/export_filtered.csv
new file mode 100644
index 0000000000..d08b318a3e
--- /dev/null
+++ b/test/fixtures/files/registrars/export_filtered.csv
@@ -0,0 +1,2 @@
+code,name,email
+BESTNAMES,Best Names,info@bestnames.test
diff --git a/test/fixtures/files/registrars/import_create.csv b/test/fixtures/files/registrars/import_create.csv
new file mode 100644
index 0000000000..8a9462646a
--- /dev/null
+++ b/test/fixtures/files/registrars/import_create.csv
@@ -0,0 +1,2 @@
+code,name,reg_no,email,address_street,address_city,address_country_code,accounting_customer_code,language
+CSVNEW,Csv New Registrar,99999,csvnew@example.test,CSV Street 1,Tallinn,US,csvnew,en
diff --git a/test/fixtures/files/registrars/import_invalid.csv b/test/fixtures/files/registrars/import_invalid.csv
new file mode 100644
index 0000000000..87d767b4fb
--- /dev/null
+++ b/test/fixtures/files/registrars/import_invalid.csv
@@ -0,0 +1,2 @@
+code,name,reg_no,email,address_street,address_city,address_country_code,accounting_customer_code,language
+,Invalid Registrar,77777,invalid@example.test,Invalid Street 5,Tallinn,EE,invalid,en
diff --git a/test/fixtures/files/registrars/import_update.csv b/test/fixtures/files/registrars/import_update.csv
new file mode 100644
index 0000000000..e2ba2ead5a
--- /dev/null
+++ b/test/fixtures/files/registrars/import_update.csv
@@ -0,0 +1,2 @@
+code,name,email,address_street,address_city,address_country_code,language
+BESTNAMES,Best Names Updated,updated-best@example.test,Updated Street 42,NY,US,en
diff --git a/test/integration/admin_area/registrars_csv_sync_test.rb b/test/integration/admin_area/registrars_csv_sync_test.rb
new file mode 100644
index 0000000000..a3c56e1a8e
--- /dev/null
+++ b/test/integration/admin_area/registrars_csv_sync_test.rb
@@ -0,0 +1,131 @@
+require 'test_helper'
+require 'csv'
+
+class AdminAreaRegistrarsCsvSyncTest < ActionDispatch::IntegrationTest
+  include Devise::Test::IntegrationHelpers
+  include ActionDispatch::TestProcess
+
+  setup do
+    sign_in users(:admin)
+    @bestnames = registrars(:bestnames)
+    @goodnames = registrars(:goodnames)
+  end
+
+  def test_exports_filtered_registrars_as_csv
+    get admin_registrars_path(format: :csv), params: { q: { name_cont: @bestnames.name } }
+
+    assert_response :ok
+    assert_equal 'text/csv', response.headers['Content-Type']
+    assert_includes response.headers['Content-Disposition'], "registrars-#{Time.zone.today}.csv"
+
+    csv = CSV.parse(response.body, headers: true)
+    exported_codes = csv.map { |row| row['code'] }
+
+    assert_includes csv.headers, 'code'
+    assert_includes exported_codes, @bestnames.code
+    refute_includes exported_codes, @goodnames.code
+  end
+
+  def test_exports_selected_registrars_as_csv
+    get admin_registrars_path(format: :csv), params: {
+      export_selected: '1',
+      registrar_ids: [@goodnames.id],
+      csv_fields: %w[name email]
+    }
+
+    assert_response :ok
+
+    csv = CSV.parse(response.body, headers: true)
+    assert_equal %w[code name email], csv.headers
+    assert_equal 1, csv.length
+    assert_equal @goodnames.code, csv[0]['code']
+  end
+
+  def test_exports_only_header_when_selected_export_has_no_ids
+    get admin_registrars_path(format: :csv), params: { export_selected: '1', registrar_ids: [''] }
+
+    assert_response :ok
+
+    csv = CSV.parse(response.body, headers: true)
+    assert_equal 0, csv.length
+    assert_includes csv.headers, 'code'
+  end
+
+  def test_import_preview_renders_summary_for_valid_csv
+    post import_preview_admin_registrars_path, params: {
+      file: fixture_file_upload('files/registrars/import_update.csv', 'text/csv'),
+      fields: %w[name email address_street address_city address_country_code language]
+    }
+
+    assert_response :success
+    assert_includes response.body, I18n.t('admin.registrars.import_preview.header')
+    assert_includes response.body, I18n.t('admin.csv_sync.preview_summary.panel_title')
+    assert_match(/name="import_token"[^>]*value="[^"]+"/, response.body)
+  end
+
+  def test_import_preview_accepts_semicolon_delimited_csv
+    semicolon_csv = <<~CSV
+      code;name;email;address_street;address_city;address_country_code;language
+      BESTNAMES;Best Names Updated Again;semicolon-best@example.test;Semicolon Street 10;NY;US;en
+    CSV
+
+    post import_preview_admin_registrars_path, params: {
+      file: Rack::Test::UploadedFile.new(StringIO.new(semicolon_csv), 'text/csv', original_filename: 'registrars-semicolon.csv'),
+      fields: %w[name email address_street address_city address_country_code language]
+    }
+
+    assert_response :success
+    assert_includes response.body, I18n.t('admin.registrars.import_preview.header')
+    assert_includes response.body, I18n.t('admin.csv_sync.preview_summary.panel_title')
+    assert_no_match(/Failed to generate import preview/, response.body)
+  end
+
+  def test_import_preview_renders_import_page_when_file_is_missing
+    post import_preview_admin_registrars_path, params: { fields: %w[name email] }
+
+    assert_response :success
+    assert_includes response.body, I18n.t('admin.registrars.import.header')
+    assert_equal I18n.t('admin.registrars.import_preview.file_required'), flash[:alert]
+  end
+
+  def test_import_apply_updates_existing_registrar
+    assert_not_equal 'updated-best@example.test', @bestnames.email
+
+    post import_apply_admin_registrars_path, params: {
+      file: fixture_file_upload('files/registrars/import_update.csv', 'text/csv'),
+      fields: %w[name email address_street address_city address_country_code language]
+    }
+
+    assert_redirected_to admin_registrars_path
+    assert_includes flash[:notice], '1 updated'
+
+    @bestnames.reload
+    assert_equal 'Best Names Updated', @bestnames.name
+    assert_equal 'updated-best@example.test', @bestnames.email
+  end
+
+  def test_import_apply_creates_new_registrar_and_cash_account
+    assert_nil Registrar.find_by(code: 'CSVNEW')
+
+    Billing::ReferenceNo.stub(:generate, '998877665544332211') do
+      post import_apply_admin_registrars_path, params: {
+        file: fixture_file_upload('files/registrars/import_create.csv', 'text/csv'),
+        fields: %w[name reg_no email address_street address_city address_country_code accounting_customer_code language]
+      }
+    end
+
+    assert_redirected_to admin_registrars_path
+    assert_includes flash[:notice], '1 created'
+
+    created = Registrar.find_by(code: 'CSVNEW')
+    assert_not_nil created
+    assert_not_nil created.cash_account
+  end
+
+  def test_import_apply_redirects_when_file_missing
+    post import_apply_admin_registrars_path, params: { fields: %w[name email] }
+
+    assert_redirected_to import_admin_registrars_path
+    assert_equal I18n.t('admin.registrars.import_apply.file_not_found'), flash[:alert]
+  end
+end
diff --git a/test/integration/admin_area/registrars_test.rb b/test/integration/admin_area/registrars_test.rb
index 3f6654033d..b250b08582 100644
--- a/test/integration/admin_area/registrars_test.rb
+++ b/test/integration/admin_area/registrars_test.rb
@@ -1,4 +1,5 @@
 require 'test_helper'
+require 'csv'
 
 class AdminAreaRegistrarsIntegrationTest < ActionDispatch::IntegrationTest
   include Devise::Test::IntegrationHelpers
@@ -19,4 +20,25 @@ def test_updates_registrar_optional_attributes
 
     assert_equal new_iban, @registrar.iban
   end
+
+  def test_exports_registrars_as_csv_with_default_fields
+    get admin_registrars_path(format: :csv)
+
+    assert_response :ok
+    assert_equal 'text/csv', response.headers['Content-Type']
+
+    csv = CSV.parse(response.body, headers: true)
+    assert_includes csv.headers, 'code'
+    assert_includes csv.headers, 'name'
+    assert(csv.find { |row| row['code'] == @registrar.code })
+  end
+
+  def test_exports_registrars_as_csv_with_selected_fields
+    get admin_registrars_path(format: :csv), params: { csv_fields: %w[reg_no email] }
+
+    assert_response :ok
+
+    csv = CSV.parse(response.body, headers: true)
+    assert_equal %w[code reg_no email], csv.headers
+  end
 end