diff --git a/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/ClaimMetadataManagementServiceImpl.java b/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/ClaimMetadataManagementServiceImpl.java
index 3cd3c6ba0349..4d73157d5138 100644
--- a/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/ClaimMetadataManagementServiceImpl.java
+++ b/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/ClaimMetadataManagementServiceImpl.java
@@ -52,6 +52,7 @@
 import java.util.Set;
 import java.util.stream.Collectors;
 
+import static org.wso2.carbon.identity.claim.metadata.mgt.util.ClaimConstants.ErrorMessage.ERROR_CODE_CANNOT_ADD_TO_EXTERNAL_DIALECT;
 import static org.wso2.carbon.identity.claim.metadata.mgt.util.ClaimConstants.ErrorMessage.ERROR_CODE_CLAIM_LENGTH_LIMIT;
 import static org.wso2.carbon.identity.claim.metadata.mgt.util.ClaimConstants.ErrorMessage.ERROR_CODE_CLAIM_PROPERTY_CHAR_LIMIT_EXCEED;
 import static org.wso2.carbon.identity.claim.metadata.mgt.util.ClaimConstants.ErrorMessage.ERROR_CODE_EMPTY_CLAIM_DIALECT;
@@ -522,7 +523,16 @@ public void addExternalClaim(ExternalClaim externalClaim, String tenantDomain) t
                             externalClaim.getMappedLocalClaim(), externalClaim.getClaimDialectURI()));
         }
 
-        // Add listener
+        ClaimMetadataEventPublisherProxy.getInstance().publishPreAddExternalClaim(tenantId, externalClaim);
+        if (MapUtils.isNotEmpty(IdentityUtil.threadLocalProperties.get()) &&
+                Boolean.TRUE.equals(IdentityUtil.threadLocalProperties.get()
+                        .get(ClaimConstants.EXTERNAL_CLAIM_ADDITION_NOT_ALLOWED_FOR_DIALECT))) {
+            IdentityUtil.threadLocalProperties.get()
+                    .remove(ClaimConstants.EXTERNAL_CLAIM_ADDITION_NOT_ALLOWED_FOR_DIALECT);
+            throw new ClaimMetadataClientException(ERROR_CODE_CANNOT_ADD_TO_EXTERNAL_DIALECT.getCode(),
+                    String.format(ERROR_CODE_CANNOT_ADD_TO_EXTERNAL_DIALECT.getMessage(),
+                            externalClaim.getClaimDialectURI()));
+        }
 
         this.unifiedClaimMetadataManager.addExternalClaim(externalClaim, tenantId);
 
diff --git a/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/util/ClaimConstants.java b/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/util/ClaimConstants.java
index 1fefe33c2c1d..84f4c5fcd492 100644
--- a/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/util/ClaimConstants.java
+++ b/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/util/ClaimConstants.java
@@ -54,6 +54,8 @@ public class ClaimConstants {
     public static final String MAX_LENGTH = "maxLength";
     public static final String IS_SYSTEM_CLAIM = "isSystemClaim";
     public static final String SHARED_PROFILE_VALUE_RESOLVING_METHOD = "SharedProfileValueResolvingMethod";
+    public static final String EXTERNAL_CLAIM_ADDITION_NOT_ALLOWED_FOR_DIALECT =
+            "ExternalClaimAdditionNotAllowedForDialect";
 
     /**
      * Enum for error messages.
@@ -112,6 +114,8 @@ public enum ErrorMessage {
         ERROR_CODE_INVALID_SHARED_PROFILE_VALUE_RESOLVING_METHOD("CMT-60014",
                 "Invalid shared profile value resolving method: %s"),
         ERROR_CODE_INVALID_ATTRIBUTE_PROFILE("CMT-600015", "Invalid attribute profile name."),
+        ERROR_CODE_CANNOT_ADD_TO_EXTERNAL_DIALECT("CMT-60016",
+                "Adding claims to dialect %s is not allowed"),
 
         // Server Errors
         ERROR_CODE_DELETE_IDN_CLAIM_MAPPED_ATTRIBUTE("65001", "Error occurred while deleting claim " +
diff --git a/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/util/DialectConfigParser.java b/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/util/DialectConfigParser.java
index e289a4f8ddc2..e03df49e22ac 100644
--- a/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/util/DialectConfigParser.java
+++ b/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/main/java/org/wso2/carbon/identity/claim/metadata/mgt/util/DialectConfigParser.java
@@ -44,6 +44,7 @@ public class DialectConfigParser {
 
     private static final String SCHEMA_FILE_NAME = "schemas.xml";
     private static final String SCHEMAS_NAMESPACE = "http://wso2.org/projects/carbon/carbon.xml";
+    private static final String DEFAULT_SCHEMA_CONFIG = "DefaultSchema";
     private static final String ADD_SCHEMA_CONFIG = "AddSchema";
     private static final String REMOVE_SCHEMA_CONFIG = "RemoveSchema";
     private static final String SCHEMAS_CONFIG = "Schemas";
@@ -54,6 +55,7 @@ public class DialectConfigParser {
     private static final Log log = LogFactory.getLog(DialectConfigParser.class);
 
     private final String schemasFilePath;
+    private Map<String, String> claimsMap = Collections.emptyMap();
     private Map<String, String> additionsToDefaultDialects = Collections.emptyMap();
     private Map<String, String> removalsFromDefaultDialects = Collections.emptyMap();
 
@@ -86,9 +88,20 @@ private void buildConfiguration() {
         try (InputStream inputStream = Files.newInputStream(schemaPath)) {
             StAXOMBuilder builder = new StAXOMBuilder(inputStream);
             OMElement rootElement = builder.getDocumentElement();
+            claimsMap = buildSchemasConfiguration(rootElement, DEFAULT_SCHEMA_CONFIG);
             additionsToDefaultDialects = buildSchemasConfiguration(rootElement, ADD_SCHEMA_CONFIG);
             removalsFromDefaultDialects = buildSchemasConfiguration(rootElement, REMOVE_SCHEMA_CONFIG);
 
+            if (additionsToDefaultDialects != null) {
+                additionsToDefaultDialects.forEach((key, value) -> {
+                    if (!claimsMap.containsKey(key)) {
+                        claimsMap.put(key, value);
+                    }
+                });
+            }
+            if (removalsFromDefaultDialects != null) {
+                removalsFromDefaultDialects.forEach((key, value) -> claimsMap.remove(key));
+            }
         } catch (IOException | XMLStreamException e) {
             throw IdentityRuntimeException.error("Error occurred while reading schema configuration in path: " +
                     schemasFilePath, e);
@@ -129,6 +142,16 @@ private Map<String, String> buildSchemasConfiguration(OMElement rootElement, Str
         return dataMap;
     }
 
+    /**
+     * Return claims supported by the server.
+     *
+     * @return Claim Map.
+     */
+    public Map<String, String> getClaimsMap() {
+
+        return claimsMap;
+    }
+
     /**
      * Get the additions to the default schema.
      *
diff --git a/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/test/resources/testSchemas/valid/schemas.xml b/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/test/resources/testSchemas/valid/schemas.xml
index ea54c22fe823..59df495ad23e 100644
--- a/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/test/resources/testSchemas/valid/schemas.xml
+++ b/components/claim-mgt/org.wso2.carbon.identity.claim.metadata.mgt/src/test/resources/testSchemas/valid/schemas.xml
@@ -1,4 +1,12 @@
 <SchemaManager xmlns="http://wso2.org/projects/carbon/carbon.xml">
+    <DefaultSchema>
+        <Schemas>
+            <Schema id="urn:ietf:params:scim:schemas:core:2.0">
+                <Attribute>urn:ietf:params:scim:schemas:core:2.0:User:id</Attribute>
+                <Attribute>urn:ietf:params:scim:schemas:core:2.0:User:meta.created</Attribute>
+            </Schema>
+        </Schemas>
+    </DefaultSchema>
     <AddSchema>
         <Schemas>
             <Schema id="urn:ietf:params:scim:schemas:core:2.0">
diff --git a/features/identity-event/org.wso2.carbon.identity.event.server.feature/resources/org.wso2.carbon.identity.event.server.feature.default.json b/features/identity-event/org.wso2.carbon.identity.event.server.feature/resources/org.wso2.carbon.identity.event.server.feature.default.json
index 1030ae90d69f..45870eee531d 100644
--- a/features/identity-event/org.wso2.carbon.identity.event.server.feature/resources/org.wso2.carbon.identity.event.server.feature.default.json
+++ b/features/identity-event/org.wso2.carbon.identity.event.server.feature/resources/org.wso2.carbon.identity.event.server.feature.default.json
@@ -204,6 +204,7 @@
     "POST_DELETE_LOCAL_CLAIM",
     "POST_UPDATE_EXTERNAL_CLAIM",
     "POST_DELETE_EXTERNAL_CLAIM",
+    "PRE_ADD_EXTERNAL_CLAIM",
     "POST_ADD_EXTERNAL_CLAIM",
     "POST_UPDATE_CLAIM_DIALECT",
     "POST_DELETE_CLAIM_DIALECT"