# IAM policies for Amazon SNS topics
<a name="two-way-sms-iam-policy"></a>

If you want AWS End User Messaging SMS to use an existing IAM role or if you create a new role, attach the following policies to that role so that AWS End User Messaging SMS can assume it. For information about how to modify the trust relationship of a role, see [Modifying a Role](https://docs.aws.amazon.com//IAM/latest/UserGuide/id_roles_manage.html) in the [https://docs.aws.amazon.com//IAM/latest/UserGuide/introduction.html](https://docs.aws.amazon.com//IAM/latest/UserGuide/introduction.html).

The following is the **trust policy** for the IAM role. In the following IAM policy, make the following changes:
+ Replace *accountId* with the unique ID for your AWS account.

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#### [ JSON ]

****  

```
{
  "Version":"2012-10-17",		 	 	 
  "Statement": [
    {
      "Sid": "SMSVoice",
      "Effect": "Allow",
      "Principal": {
        "Service": "sms-voice.amazonaws.com"
      },
      "Action": "sts:AssumeRole",
      "Condition": {
        "StringEquals": {
          "aws:SourceAccount": "accountId"
        }
      }
    }
  ]
}
```

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The following is the **permission policy** for the IAM role. The `SMSVoiceAllowSNSPublish` Sid is a permission policy to allow for publishing to Amazon SNS topics and the `SMSVoiceAllowEncryptedSNSTopics` Sid is an option for encrypted Amazon SNS topics.

In the following IAM permission policy, make the following changes:
+ Replace *partition* with the AWS partition that you use AWS End User Messaging SMS in.
+ Replace *region* with the AWS Region that you use AWS End User Messaging SMS in.
+ Replace *accountId* with the unique ID for your AWS account.
+ Replace *snsTopicArn* with the Amazon SNS topics that will receive messages.

------
#### [ JSON ]

****  

```
{
    "Version":"2012-10-17",		 	 	 
    "Statement": [
        {
            "Sid": "SMSVoiceAllowSNSPublish",
            "Effect": "Allow",
            "Action": "sns:Publish",
            "Resource": "arn:aws:sns:us-east-1:111122223333:snsTopicArn",
            "Condition": {
                "StringEquals": {
                "aws:ResourceAccount": "111122223333"
                }
            }
        },
        {
            "Sid": "SMSVoiceAllowEncryptedSNSTopics",
            "Effect": "Allow",
            "Action": [
                "kms:Decrypt",
                "kms:GenerateDataKey*"
            ],
            "Resource": "*",
            "Condition": {
                "StringEquals": {
                "kms:EncryptionContext:aws:sns:topicArn": "arn:aws:sns:us-east-1:111122223333:snsTopicArn",
                    "aws:CalledViaLast": "sns.amazonaws.com"
                }
            }
        }
    ]
}
```

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