diff --git a/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.common/src/main/java/org/wso2/carbon/identity/api/server/idp/common/Constants.java b/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.common/src/main/java/org/wso2/carbon/identity/api/server/idp/common/Constants.java
index d578b8f918..fe30c0eb24 100644
--- a/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.common/src/main/java/org/wso2/carbon/identity/api/server/idp/common/Constants.java
+++ b/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.common/src/main/java/org/wso2/carbon/identity/api/server/idp/common/Constants.java
@@ -158,6 +158,8 @@ public enum ErrorMessage {
                 "Unable to decode the provided authenticator ID %s."),
         ERROR_CODE_NO_SYSTEM_AUTHENTICATOR_FOUND("60043", "No system authenticator found.",
                 "No system authenticator found for the provided authenticator Id %s."),
+        ERROR_COED_MULTIPLE_USER_DEFINED_AUTHENTICATORS_FOUND("60044", "Multiple authenticators found.",
+                "Multiple user defined authenticators are not allowed."),
 
         // Server Error starting from 650xx.
         ERROR_CODE_ERROR_ADDING_IDP("65002",
diff --git a/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.v1/src/main/java/org/wso2/carbon/identity/api/server/idp/v1/core/ServerIdpManagementService.java b/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.v1/src/main/java/org/wso2/carbon/identity/api/server/idp/v1/core/ServerIdpManagementService.java
index 425f298f00..50ac07fe64 100644
--- a/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.v1/src/main/java/org/wso2/carbon/identity/api/server/idp/v1/core/ServerIdpManagementService.java
+++ b/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.v1/src/main/java/org/wso2/carbon/identity/api/server/idp/v1/core/ServerIdpManagementService.java
@@ -1779,6 +1779,10 @@ private void updateFederatedAuthenticatorConfig(IdentityProvider idp, FederatedA
                 } else {
                     definedByType = resolveDefinedByTypeToUpdateFederatedAuthenticator(authenticatorName);
                 }
+                if (definedByType == DefinedByType.USER && federatedAuthenticators.size() > 1) {
+                    throw handleException(Response.Status.BAD_REQUEST,
+                            Constants.ErrorMessage.ERROR_COED_MULTIPLE_USER_DEFINED_AUTHENTICATORS_FOUND, null);
+                }
                 FederatedAuthenticatorConfig authConfig = FederatedAuthenticatorConfigBuilderFactory.build(
                         authenticator, authenticatorName, definedByType);
 
diff --git a/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.v1/src/main/java/org/wso2/carbon/identity/api/server/idp/v1/impl/FederatedAuthenticatorConfigBuilderFactory.java b/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.v1/src/main/java/org/wso2/carbon/identity/api/server/idp/v1/impl/FederatedAuthenticatorConfigBuilderFactory.java
index 7f2d7800a6..89e00d1e86 100644
--- a/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.v1/src/main/java/org/wso2/carbon/identity/api/server/idp/v1/impl/FederatedAuthenticatorConfigBuilderFactory.java
+++ b/components/org.wso2.carbon.identity.api.server.idp/org.wso2.carbon.identity.api.server.idp.v1/src/main/java/org/wso2/carbon/identity/api/server/idp/v1/impl/FederatedAuthenticatorConfigBuilderFactory.java
@@ -38,11 +38,7 @@
 import org.wso2.carbon.idp.mgt.IdentityProviderManagementServerException;
 
 import java.nio.charset.StandardCharsets;
-import java.util.Arrays;
-import java.util.Base64;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
+import java.util.*;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
@@ -184,17 +180,22 @@ private static UserDefinedFederatedAuthenticatorConfig createUserDefinedFederate
 
         validateUserDefinedFederatedAuthenticatorModel(config);
 
-        UserDefinedFederatedAuthenticatorConfig authConfig = new UserDefinedFederatedAuthenticatorConfig();
-        UserDefinedAuthenticatorEndpointConfig.UserDefinedAuthenticatorEndpointConfigBuilder endpointConfigBuilder =
-                new UserDefinedAuthenticatorEndpointConfig.UserDefinedAuthenticatorEndpointConfigBuilder();
-        endpointConfigBuilder.uri(config.endpoint.getUri());
-        endpointConfigBuilder.authenticationType(config.endpoint.getAuthentication().getType().toString());
-        endpointConfigBuilder.authenticationProperties(config.endpoint.getAuthentication().getProperties()
-                .entrySet().stream().collect(Collectors.toMap(
-                        Map.Entry::getKey, entry -> entry.getValue().toString())));
-        authConfig.setEndpointConfig(endpointConfigBuilder.build());
-
-        return authConfig;
+        try {
+            UserDefinedFederatedAuthenticatorConfig authConfig = new UserDefinedFederatedAuthenticatorConfig();
+            UserDefinedAuthenticatorEndpointConfig.UserDefinedAuthenticatorEndpointConfigBuilder endpointConfigBuilder =
+                    new UserDefinedAuthenticatorEndpointConfig.UserDefinedAuthenticatorEndpointConfigBuilder();
+            endpointConfigBuilder.uri(config.endpoint.getUri());
+            endpointConfigBuilder.authenticationType(config.endpoint.getAuthentication().getType().toString());
+            endpointConfigBuilder.authenticationProperties(config.endpoint.getAuthentication().getProperties()
+                    .entrySet().stream().collect(Collectors.toMap(
+                            Map.Entry::getKey, entry -> entry.getValue().toString())));
+            authConfig.setEndpointConfig(endpointConfigBuilder.build());
+
+            return authConfig;
+        } catch (NoSuchElementException e) {
+            throw new IdentityProviderManagementClientException(Constants.ErrorMessage
+                    .ERROR_CODE_INVALID_INPUT.getCode(), e.getMessage());
+        }
     }
 
     private static void validateUserDefinedFederatedAuthenticatorModel(Config config)