diff --git a/octopus-server/src/main/java/octopus/teamcity/server/OctopusBuildInformationRunType.java b/octopus-server/src/main/java/octopus/teamcity/server/OctopusBuildInformationRunType.java
index 9cc54b05..3998b9be 100644
--- a/octopus-server/src/main/java/octopus/teamcity/server/OctopusBuildInformationRunType.java
+++ b/octopus-server/src/main/java/octopus/teamcity/server/OctopusBuildInformationRunType.java
@@ -16,6 +16,9 @@
 
 package octopus.teamcity.server;
 
+import static octopus.teamcity.server.PropertiesValidator.checkCredentialsUnlessUsingConnection;
+import static octopus.teamcity.server.PropertiesValidator.checkNotEmpty;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -25,7 +28,6 @@
 import jetbrains.buildServer.serverSide.PropertiesProcessor;
 import jetbrains.buildServer.serverSide.RunType;
 import jetbrains.buildServer.serverSide.RunTypeRegistry;
-import jetbrains.buildServer.util.StringUtil;
 import jetbrains.buildServer.web.openapi.PluginDescriptor;
 import octopus.teamcity.common.OctopusConstants;
 import octopus.teamcity.server.connection.ConnectionInlineFieldCleaner;
@@ -62,27 +64,13 @@ public String getDescription() {
   public PropertiesProcessor getRunnerPropertiesProcessor() {
     final OctopusConstants c = new OctopusConstants();
     return new PropertiesProcessor() {
-      private void checkNotEmpty(
-          @NotNull final Map<String, String> properties,
-          @NotNull final String key,
-          @NotNull final String message,
-          @NotNull final Collection<InvalidProperty> res) {
-        if (jetbrains.buildServer.util.StringUtil.isEmptyOrSpaces(properties.get(key))) {
-          res.add(new InvalidProperty(key, message));
-        }
-      }
-
       @Override
       @NotNull
       public Collection<InvalidProperty> process(@Nullable final Map<String, String> p) {
         final Collection<InvalidProperty> result = new ArrayList<InvalidProperty>();
         if (p == null) return result;
 
-        final boolean usingConnection = !StringUtil.isEmptyOrSpaces(p.get(c.getConnectionIdKey()));
-        if (!usingConnection) {
-          checkNotEmpty(p, c.getServerKey(), "Server must be specified", result);
-          checkNotEmpty(p, c.getApiKey(), "API key must be specified", result);
-        }
+        checkCredentialsUnlessUsingConnection(p, c, result);
         checkNotEmpty(p, c.getPackageIdKey(), "Package ID must be specified", result);
         checkNotEmpty(p, c.getPackageVersionKey(), "Package version be specified", result);
 
diff --git a/octopus-server/src/main/java/octopus/teamcity/server/OctopusCreateReleaseRunType.java b/octopus-server/src/main/java/octopus/teamcity/server/OctopusCreateReleaseRunType.java
index acd959ec..3158931a 100644
--- a/octopus-server/src/main/java/octopus/teamcity/server/OctopusCreateReleaseRunType.java
+++ b/octopus-server/src/main/java/octopus/teamcity/server/OctopusCreateReleaseRunType.java
@@ -1,5 +1,8 @@
 package octopus.teamcity.server;
 
+import static octopus.teamcity.server.PropertiesValidator.checkCredentialsUnlessUsingConnection;
+import static octopus.teamcity.server.PropertiesValidator.checkNotEmpty;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -9,7 +12,6 @@
 import jetbrains.buildServer.serverSide.PropertiesProcessor;
 import jetbrains.buildServer.serverSide.RunType;
 import jetbrains.buildServer.serverSide.RunTypeRegistry;
-import jetbrains.buildServer.util.StringUtil;
 import jetbrains.buildServer.web.openapi.PluginDescriptor;
 import octopus.teamcity.common.OctopusConstants;
 import octopus.teamcity.server.connection.ConnectionInlineFieldCleaner;
@@ -46,27 +48,13 @@ public String getDescription() {
   public PropertiesProcessor getRunnerPropertiesProcessor() {
     final OctopusConstants c = new OctopusConstants();
     return new PropertiesProcessor() {
-      private void checkNotEmpty(
-          @NotNull final Map<String, String> properties,
-          @NotNull final String key,
-          @NotNull final String message,
-          @NotNull final Collection<InvalidProperty> res) {
-        if (jetbrains.buildServer.util.StringUtil.isEmptyOrSpaces(properties.get(key))) {
-          res.add(new InvalidProperty(key, message));
-        }
-      }
-
       @Override
       @NotNull
       public Collection<InvalidProperty> process(@Nullable final Map<String, String> p) {
         final Collection<InvalidProperty> result = new ArrayList<InvalidProperty>();
         if (p == null) return result;
 
-        final boolean usingConnection = !StringUtil.isEmptyOrSpaces(p.get(c.getConnectionIdKey()));
-        if (!usingConnection) {
-          checkNotEmpty(p, c.getApiKey(), "API key must be specified", result);
-          checkNotEmpty(p, c.getServerKey(), "Server must be specified", result);
-        }
+        checkCredentialsUnlessUsingConnection(p, c, result);
         checkNotEmpty(p, c.getProjectNameKey(), "Project name must be specified", result);
 
         if (result.isEmpty()) {
diff --git a/octopus-server/src/main/java/octopus/teamcity/server/OctopusDeployReleaseRunType.java b/octopus-server/src/main/java/octopus/teamcity/server/OctopusDeployReleaseRunType.java
index cf24f63e..f2524e87 100644
--- a/octopus-server/src/main/java/octopus/teamcity/server/OctopusDeployReleaseRunType.java
+++ b/octopus-server/src/main/java/octopus/teamcity/server/OctopusDeployReleaseRunType.java
@@ -16,6 +16,9 @@
 
 package octopus.teamcity.server;
 
+import static octopus.teamcity.server.PropertiesValidator.checkCredentialsUnlessUsingConnection;
+import static octopus.teamcity.server.PropertiesValidator.checkNotEmpty;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -25,7 +28,6 @@
 import jetbrains.buildServer.serverSide.PropertiesProcessor;
 import jetbrains.buildServer.serverSide.RunType;
 import jetbrains.buildServer.serverSide.RunTypeRegistry;
-import jetbrains.buildServer.util.StringUtil;
 import jetbrains.buildServer.web.openapi.PluginDescriptor;
 import octopus.teamcity.common.OctopusConstants;
 import octopus.teamcity.server.connection.ConnectionInlineFieldCleaner;
@@ -62,27 +64,13 @@ public String getDescription() {
   public PropertiesProcessor getRunnerPropertiesProcessor() {
     final OctopusConstants c = new OctopusConstants();
     return new PropertiesProcessor() {
-      private void checkNotEmpty(
-          @NotNull final Map<String, String> properties,
-          @NotNull final String key,
-          @NotNull final String message,
-          @NotNull final Collection<InvalidProperty> res) {
-        if (jetbrains.buildServer.util.StringUtil.isEmptyOrSpaces(properties.get(key))) {
-          res.add(new InvalidProperty(key, message));
-        }
-      }
-
       @Override
       @NotNull
       public Collection<InvalidProperty> process(@Nullable final Map<String, String> p) {
         final Collection<InvalidProperty> result = new ArrayList<InvalidProperty>();
         if (p == null) return result;
 
-        final boolean usingConnection = !StringUtil.isEmptyOrSpaces(p.get(c.getConnectionIdKey()));
-        if (!usingConnection) {
-          checkNotEmpty(p, c.getApiKey(), "API key must be specified", result);
-          checkNotEmpty(p, c.getServerKey(), "Server must be specified", result);
-        }
+        checkCredentialsUnlessUsingConnection(p, c, result);
         checkNotEmpty(p, c.getProjectNameKey(), "Project name must be specified", result);
         checkNotEmpty(p, c.getReleaseNumberKey(), "Release number must be specified", result);
         checkNotEmpty(p, c.getDeployToKey(), "Deploy to must be specified", result);
diff --git a/octopus-server/src/main/java/octopus/teamcity/server/OctopusPackPackageRunType.java b/octopus-server/src/main/java/octopus/teamcity/server/OctopusPackPackageRunType.java
index 610dc292..6e0e65a9 100644
--- a/octopus-server/src/main/java/octopus/teamcity/server/OctopusPackPackageRunType.java
+++ b/octopus-server/src/main/java/octopus/teamcity/server/OctopusPackPackageRunType.java
@@ -16,6 +16,8 @@
 
 package octopus.teamcity.server;
 
+import static octopus.teamcity.server.PropertiesValidator.checkNotEmpty;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -60,16 +62,6 @@ public String getDescription() {
   public PropertiesProcessor getRunnerPropertiesProcessor() {
     final OctopusConstants c = new OctopusConstants();
     return new PropertiesProcessor() {
-      private void checkNotEmpty(
-          @NotNull final Map<String, String> properties,
-          @NotNull final String key,
-          @NotNull final String message,
-          @NotNull final Collection<InvalidProperty> res) {
-        if (jetbrains.buildServer.util.StringUtil.isEmptyOrSpaces(properties.get(key))) {
-          res.add(new InvalidProperty(key, message));
-        }
-      }
-
       @Override
       @NotNull
       public Collection<InvalidProperty> process(@Nullable final Map<String, String> p) {
diff --git a/octopus-server/src/main/java/octopus/teamcity/server/OctopusPromoteReleaseRunType.java b/octopus-server/src/main/java/octopus/teamcity/server/OctopusPromoteReleaseRunType.java
index 70bbae5c..11725211 100644
--- a/octopus-server/src/main/java/octopus/teamcity/server/OctopusPromoteReleaseRunType.java
+++ b/octopus-server/src/main/java/octopus/teamcity/server/OctopusPromoteReleaseRunType.java
@@ -16,6 +16,9 @@
 
 package octopus.teamcity.server;
 
+import static octopus.teamcity.server.PropertiesValidator.checkCredentialsUnlessUsingConnection;
+import static octopus.teamcity.server.PropertiesValidator.checkNotEmpty;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -25,7 +28,6 @@
 import jetbrains.buildServer.serverSide.PropertiesProcessor;
 import jetbrains.buildServer.serverSide.RunType;
 import jetbrains.buildServer.serverSide.RunTypeRegistry;
-import jetbrains.buildServer.util.StringUtil;
 import jetbrains.buildServer.web.openapi.PluginDescriptor;
 import octopus.teamcity.common.OctopusConstants;
 import octopus.teamcity.server.connection.ConnectionInlineFieldCleaner;
@@ -62,27 +64,13 @@ public String getDescription() {
   public PropertiesProcessor getRunnerPropertiesProcessor() {
     final OctopusConstants c = new OctopusConstants();
     return new PropertiesProcessor() {
-      private void checkNotEmpty(
-          @NotNull final Map<String, String> properties,
-          @NotNull final String key,
-          @NotNull final String message,
-          @NotNull final Collection<InvalidProperty> res) {
-        if (jetbrains.buildServer.util.StringUtil.isEmptyOrSpaces(properties.get(key))) {
-          res.add(new InvalidProperty(key, message));
-        }
-      }
-
       @Override
       @NotNull
       public Collection<InvalidProperty> process(@Nullable final Map<String, String> p) {
         final Collection<InvalidProperty> result = new ArrayList<InvalidProperty>();
         if (p == null) return result;
 
-        final boolean usingConnection = !StringUtil.isEmptyOrSpaces(p.get(c.getConnectionIdKey()));
-        if (!usingConnection) {
-          checkNotEmpty(p, c.getApiKey(), "API key must be specified", result);
-          checkNotEmpty(p, c.getServerKey(), "Server must be specified", result);
-        }
+        checkCredentialsUnlessUsingConnection(p, c, result);
         checkNotEmpty(p, c.getProjectNameKey(), "Project name must be specified", result);
         checkNotEmpty(
             p, c.getPromoteFromKey(), "Environment to promote from must be specified", result);
diff --git a/octopus-server/src/main/java/octopus/teamcity/server/OctopusPushPackageRunType.java b/octopus-server/src/main/java/octopus/teamcity/server/OctopusPushPackageRunType.java
index cd2d35e3..798c69e4 100644
--- a/octopus-server/src/main/java/octopus/teamcity/server/OctopusPushPackageRunType.java
+++ b/octopus-server/src/main/java/octopus/teamcity/server/OctopusPushPackageRunType.java
@@ -16,6 +16,9 @@
 
 package octopus.teamcity.server;
 
+import static octopus.teamcity.server.PropertiesValidator.checkCredentialsUnlessUsingConnection;
+import static octopus.teamcity.server.PropertiesValidator.checkNotEmpty;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -25,7 +28,6 @@
 import jetbrains.buildServer.serverSide.PropertiesProcessor;
 import jetbrains.buildServer.serverSide.RunType;
 import jetbrains.buildServer.serverSide.RunTypeRegistry;
-import jetbrains.buildServer.util.StringUtil;
 import jetbrains.buildServer.web.openapi.PluginDescriptor;
 import octopus.teamcity.common.OctopusConstants;
 import octopus.teamcity.server.connection.ConnectionInlineFieldCleaner;
@@ -62,27 +64,13 @@ public String getDescription() {
   public PropertiesProcessor getRunnerPropertiesProcessor() {
     final OctopusConstants c = new OctopusConstants();
     return new PropertiesProcessor() {
-      private void checkNotEmpty(
-          @NotNull final Map<String, String> properties,
-          @NotNull final String key,
-          @NotNull final String message,
-          @NotNull final Collection<InvalidProperty> res) {
-        if (jetbrains.buildServer.util.StringUtil.isEmptyOrSpaces(properties.get(key))) {
-          res.add(new InvalidProperty(key, message));
-        }
-      }
-
       @Override
       @NotNull
       public Collection<InvalidProperty> process(@Nullable final Map<String, String> p) {
         final Collection<InvalidProperty> result = new ArrayList<InvalidProperty>();
         if (p == null) return result;
 
-        final boolean usingConnection = !StringUtil.isEmptyOrSpaces(p.get(c.getConnectionIdKey()));
-        if (!usingConnection) {
-          checkNotEmpty(p, c.getApiKey(), "API key must be specified", result);
-          checkNotEmpty(p, c.getServerKey(), "Server must be specified", result);
-        }
+        checkCredentialsUnlessUsingConnection(p, c, result);
         checkNotEmpty(p, c.getPackagePathsKey(), "Package paths must be specified", result);
 
         if (result.isEmpty()) {
diff --git a/octopus-server/src/main/java/octopus/teamcity/server/PropertiesValidator.java b/octopus-server/src/main/java/octopus/teamcity/server/PropertiesValidator.java
new file mode 100644
index 00000000..33d78de9
--- /dev/null
+++ b/octopus-server/src/main/java/octopus/teamcity/server/PropertiesValidator.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) Octopus Deploy and contributors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+ *  these files except in compliance with the License. You may obtain a copy of the
+ * License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed
+ * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+ * CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+
+package octopus.teamcity.server;
+
+import java.util.Collection;
+import java.util.Map;
+
+import jetbrains.buildServer.serverSide.InvalidProperty;
+import jetbrains.buildServer.util.StringUtil;
+import octopus.teamcity.common.OctopusConstants;
+import org.jetbrains.annotations.NotNull;
+
+/** Shared validation helpers for run type {@code PropertiesProcessor}s. */
+public final class PropertiesValidator {
+
+  private PropertiesValidator() {}
+
+  /**
+   * Adds an {@link InvalidProperty} to {@code result} when the value for {@code key} is missing or
+   * blank.
+   */
+  public static void checkNotEmpty(
+      @NotNull final Map<String, String> properties,
+      @NotNull final String key,
+      @NotNull final String message,
+      @NotNull final Collection<InvalidProperty> result) {
+    if (StringUtil.isEmptyOrSpaces(properties.get(key))) {
+      result.add(new InvalidProperty(key, message));
+    }
+  }
+
+  /**
+   * Requires the inline server URL and API key unless a reusable connection is selected (in which
+   * case those credentials come from the connection at build start).
+   */
+  public static void checkCredentialsUnlessUsingConnection(
+      @NotNull final Map<String, String> properties,
+      @NotNull final OctopusConstants constants,
+      @NotNull final Collection<InvalidProperty> result) {
+    final boolean usingConnection =
+        !StringUtil.isEmptyOrSpaces(properties.get(constants.getConnectionIdKey()));
+    if (!usingConnection) {
+      checkNotEmpty(properties, constants.getServerKey(), "Server must be specified", result);
+      checkNotEmpty(properties, constants.getApiKey(), "API key must be specified", result);
+    }
+  }
+}