diff --git a/proxies/live/apiproxy/targets/target.xml b/proxies/live/apiproxy/targets/target.xml
index c9c0bfdd3..7aab331d7 100644
--- a/proxies/live/apiproxy/targets/target.xml
+++ b/proxies/live/apiproxy/targets/target.xml
@@ -18,10 +18,14 @@
         <SSLInfo>
             <Enabled>true</Enabled>
         </SSLInfo>
-        <LoadBalancer>
-            <Server name="{{ TARGET_SERVER_OVERRIDE | default('communications-manager-target') }}"/>
-        </LoadBalancer>
-        <Path>{requestpath}</Path>
+        {% if ENVIRONMENT_TYPE == 'sandbox' %}
+            <LoadBalancer>
+                <Server name="{{ TARGET_SERVER_OVERRIDE | default('communications-manager-target') }}"/>
+            </LoadBalancer>
+            <Path>{requestpath}</Path>
+        {% else %}
+            <URL>https://comms-apim.de-chel5.communications.national.nhs.uk</URL>
+        {% endif %}
         <Properties>
             <Property name="io.timeout.millis">29000</Property>
         </Properties>
diff --git a/proxies/shared/policies/AssignMessage.MessageBatches.Create.Request.xml b/proxies/shared/policies/AssignMessage.MessageBatches.Create.Request.xml
index 3dfbc673b..29551f842 100644
--- a/proxies/shared/policies/AssignMessage.MessageBatches.Create.Request.xml
+++ b/proxies/shared/policies/AssignMessage.MessageBatches.Create.Request.xml
@@ -16,10 +16,17 @@
         <Name>target.copy.pathsuffix</Name>
         <Value>false</Value>
     </AssignVariable>
-    <AssignVariable>
-        <Name>requestpath</Name>
-        <Value>/api/v1/send</Value>
-    </AssignVariable>
+    {% if ENVIRONMENT_TYPE == 'sandbox' %}
+       <AssignVariable>
+           <Name>requestpath</Name>
+           <Value>/api/v1/send</Value>
+       </AssignVariable>
+    {% else %}
+        <AssignVariable>
+            <Name>target.url</Name>
+            <Value>https://comms-apim.de-chel5.communications.national.nhs.uk/api/v1/send</Value>
+        </AssignVariable>
+    {% endif %}
     <Set>
         <Payload contentType="application/json" variablePrefix="%" variableSuffix="#">%data.payload#</Payload>
         <Headers>
diff --git a/proxies/shared/policies/AssignMessage.Messages.Create.Request.xml b/proxies/shared/policies/AssignMessage.Messages.Create.Request.xml
index 2a8e9cd5c..df94ecc6b 100644
--- a/proxies/shared/policies/AssignMessage.Messages.Create.Request.xml
+++ b/proxies/shared/policies/AssignMessage.Messages.Create.Request.xml
@@ -16,10 +16,17 @@
         <Name>target.copy.pathsuffix</Name>
         <Value>false</Value>
     </AssignVariable>
-    <AssignVariable>
-        <Name>requestpath</Name>
-        <Value>/api/v1/messages</Value>
-    </AssignVariable>
+    {% if ENVIRONMENT_TYPE == 'sandbox' %}
+       <AssignVariable>
+           <Name>requestpath</Name>
+           <Value>/api/v1/messages</Value>
+       </AssignVariable>
+    {% else %}
+        <AssignVariable>
+            <Name>target.url</Name>
+            <Value>https://comms-apim.de-chel5.communications.national.nhs.uk/api/v1/messages</Value>
+        </AssignVariable>
+    {% endif %}
     <Set>
         <Payload contentType="application/json" variablePrefix="%" variableSuffix="#">%data.payload#</Payload>
         <Headers>
diff --git a/proxies/shared/policies/AssignMessage.Messages.GetSingle.Request.xml b/proxies/shared/policies/AssignMessage.Messages.GetSingle.Request.xml
index ce54ec959..fc823c567 100644
--- a/proxies/shared/policies/AssignMessage.Messages.GetSingle.Request.xml
+++ b/proxies/shared/policies/AssignMessage.Messages.GetSingle.Request.xml
@@ -16,10 +16,17 @@
         <Name>target.copy.pathsuffix</Name>
         <Value>false</Value>
     </AssignVariable>
-    <AssignVariable>
-        <Name>requestpath</Name>
-        <Template>/api/v1/messages/{data.messageId}</Template>
-    </AssignVariable>
+    {% if ENVIRONMENT_TYPE == 'sandbox' %}
+       <AssignVariable>
+           <Name>requestpath</Name>
+           <Template>/api/v1/messages/{data.messageId}</Template>
+       </AssignVariable>
+    {% else %}
+        <AssignVariable>
+            <Name>target.url</Name>
+            <Value>https://comms-apim.de-chel5.communications.national.nhs.uk/api/v1/messages/{data.messageId}</Value>
+        </AssignVariable>
+    {% endif %}
     <Set>
         <Headers>
             <Header name="X-Correlation-Id">{backendCorrelationId}</Header>
diff --git a/proxies/shared/policies/AssignMessage.NhsAppAccounts.Get.Request.xml b/proxies/shared/policies/AssignMessage.NhsAppAccounts.Get.Request.xml
index 6d71f721a..b70542dfc 100644
--- a/proxies/shared/policies/AssignMessage.NhsAppAccounts.Get.Request.xml
+++ b/proxies/shared/policies/AssignMessage.NhsAppAccounts.Get.Request.xml
@@ -16,10 +16,17 @@
         <Name>target.copy.pathsuffix</Name>
         <Value>false</Value>
     </AssignVariable>
-    <AssignVariable>
-        <Name>requestpath</Name>
-        <Value>/api/channels/nhsapp/accounts</Value>
-    </AssignVariable>
+    {% if ENVIRONMENT_TYPE == 'sandbox' %}
+       <AssignVariable>
+           <Name>requestpath</Name>
+           <Value>/api/channels/nhsapp/accounts</Value>
+       </AssignVariable>
+    {% else %}
+        <AssignVariable>
+            <Name>target.url</Name>
+            <Value>https://comms-apim.de-chel5.communications.national.nhs.uk/api/channels/nhsapp/accounts</Value>
+        </AssignVariable>
+    {% endif %}
     <Set>
         <Headers>
             <Header name="X-Correlation-Id">{backendCorrelationId}</Header>
diff --git a/specification/documentation/CreateMessageBatch.md b/specification/documentation/CreateMessageBatch.md
index c0b9a0c0d..af66080fb 100644
--- a/specification/documentation/CreateMessageBatch.md
+++ b/specification/documentation/CreateMessageBatch.md
@@ -17,7 +17,7 @@ The per message reference (`messageReference`) needs to be unique within the mes
 
 You may be required to send through specific personalisation fields based upon the routing plan (`routingPlanId`). These will have been setup during your [onboarding](#overview--onboarding) process.
 
-These are validated according to the routing plan when we store your message batch. If there are missing values then the entire batch will be rejected with a `CM_INVALID_VALUE` code. The detail and source fields will provide further information about the error.
+Messages that are missing required personalisation fields, or have personalisation content that is too long for the routing plan that it is used in, will be accepted by the API but will not be sent.
 
 ### Sandbox