# Using service-linked roles for AWS End User Messaging SMS
<a name="using-service-linked-roles"></a>

AWS End User Messaging SMS uses AWS Identity and Access Management (IAM) [service-linked roles](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles.html#id_roles_terms-and-concepts). A service-linked role is a unique type of IAM role that is linked directly to AWS End User Messaging SMS. Service-linked roles are predefined by AWS End User Messaging SMS and include all the permissions that the service requires to call other AWS services on your behalf. 

A service-linked role makes setting up AWS End User Messaging SMS easier because you don’t have to manually add the necessary permissions. AWS End User Messaging SMS defines the permissions of its service-linked roles, and unless defined otherwise, only AWS End User Messaging SMS can assume its roles. The defined permissions include the trust policy and the permissions policy, and that permissions policy cannot be attached to any other IAM entity.

You can delete a service-linked role only after first deleting their related resources. This protects your AWS End User Messaging SMS resources because you can't inadvertently remove permission to access the resources.

For information about other services that support service-linked roles, see [AWS services that work with IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_aws-services-that-work-with-iam.html) and look for the services that have **Yes** in the **Service-linked roles** column. Choose a **Yes** with a link to view the service-linked role documentation for that service.

## Service-linked role permissions for AWS End User Messaging SMS
<a name="slr-permissions"></a>

AWS End User Messaging SMS uses the service-linked role named **AWSServiceRoleForSMSVoice** – Allows SMSVoice to publish metrics to CloudWatch on your behalf.

The AWSServiceRoleForSMSVoice service-linked role trusts the following services to assume the role:
+ `sms-voice.amazonaws.com`

The role permissions policy named SMSVoiceServiceRolePolicy allows AWS End User Messaging SMS to complete the following actions on the specified resources:
+ Action: `cloudwatch:PutMetricData` on `any metric in the AWS/SMSVoice namespace`

You must configure permissions to allow your users, groups, or roles to create, edit, or delete a service-linked role. For more information, see [Service-linked role permissions](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_create-service-linked-role.html#service-linked-role-permissions) in the *IAM User Guide*.

## Creating a service-linked role for AWS End User Messaging SMS
<a name="create-slr"></a>

You don't need to manually create a service-linked role. When you use any of the following actions `CreateConfigurationSet`, `CreateOptOutList`, `CreatePool`, `CreateProtectConfiguration`, `CreateRegistration`, `CreateRegistrationAttachment`, `CreateVerifiedDestinationNumber`, `RequestPhoneNumber`, or `RequestSenderId` in the AWS Management Console, the AWS CLI, or the AWS API, AWS End User Messaging SMS creates the service-linked role for you. 

If you delete this service-linked role, and then need to create it again, you can use the same process to recreate the role in your account. When you use any of the following actions `CreateConfigurationSet`, `CreateOptOutList`, `CreatePool`, `CreateProtectConfiguration`, `CreateRegistration`, `CreateRegistrationAttachment`, `CreateVerifiedDestinationNumber`, `RequestPhoneNumber`, or `RequestSenderId`, AWS End User Messaging SMS creates the service-linked role for you again. 

You can also use the IAM console to create a service-linked role with the **AWSEndUserMessagingSMS - Metrics** use case. In the AWS CLI or the AWS API, create a service-linked role with the `sms-voice.amazonaws.com` service name. For more information, see [Creating a service-linked role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_create-service-linked-role.html#create-service-linked-role) in the *IAM User Guide*. If you delete this service-linked role, you can use this same process to create the role again.

## Editing a service-linked role for AWS End User Messaging SMS
<a name="edit-slr"></a>

AWS End User Messaging SMS does not allow you to edit the AWSServiceRoleForSMSVoice service-linked role. After you create a service-linked role, you cannot change the name of the role because various entities might reference the role. However, you can edit the description of the role using IAM. For more information, see [Editing a service-linked role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_create-service-linked-role.html#edit-service-linked-role) in the *IAM User Guide*.

## Deleting a service-linked role for AWS End User Messaging SMS
<a name="delete-slr"></a>

If you no longer need to use a feature or service that requires a service-linked role, we recommend that you delete that role. That way you don’t have an unused entity that is not actively monitored or maintained. However, you must clean up the resources for your service-linked role before you can manually delete it.

**Note**  
If the AWS End User Messaging SMS service is using the role when you try to delete the resources, then the deletion might fail. If that happens, wait for a few minutes and try the operation again.

**To delete AWS End User Messaging SMS resources used by the AWSServiceRoleForSMSVoice**

1. Verify you have no configuration sets, registrations, protect configurations, sender IDs, pools, long codes, and that you have not used AWS End User Messaging SMS in the last 30 days.

1. Call the iam DeleteServiceLinkedRole api to remove the role, for more information see [Deleting a service-linked role](https://docs.aws.amazon.com//IAM/latest/UserGuide/id_roles_create-service-linked-role.html#delete-service-linked-role).

**To manually delete the service-linked role using IAM**

Use the IAM console, the AWS CLI, or the AWS API to delete the AWSServiceRoleForSMSVoice service-linked role. For more information, see [Deleting a service-linked role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_create-service-linked-role.html#delete-service-linked-role) in the *IAM User Guide*.

## Supported Regions for AWS End User Messaging SMS service-linked roles
<a name="slr-regions"></a>

AWS End User Messaging SMS supports using service-linked roles in all of the Regions where the service is available. For more information, see [AWS End User Messaging endpoints and quotas](https://docs.aws.amazon.com/general/latest/gr/end-user-messaging.html).