Why am I getting Invalid SNS topic ARN when creating a Budget Alert

Question

I'm simply attempting to setup a budget alert buy am getting the error Invalid SNS topic ARN when attempting to specify an SNS ARN for the alert.

I followed the steps below:

1. Created a new SNS Topic with SMS as the protocol.
2. Created a subscription to the topic (a US phone number).
3. Tested the subscription by sending a text (this worked).
4. Copied the ARN under the ARN column on the Topics section in AWS SNS.
5. Checked Notify via Amazon Simple Notification Service (SNS) topic and entered the ARN from #4.
6. I get the error Invalid SNS topic ARN next to the SNS Topic ARN field, immediately after copying-and-pasting the ARN into the field.

What's up? I know it's the correct ARN because I copied it directly from the console. Also, as far as I understand, Budgets and their alerts aren't tied the a specific region, although SNS Topics are (the topic is in us-east-2 N. Virginia).

Please let me know if you need more specifics.

Answer 1

Make sure you have allowed budget.amazonaws.com to be able to publish messages to this SNS topic in the SNS topic's resource based policy.

Add the following statement to the policy

{
    "Sid": "ExampleSid123456789012",
    "Effect": "Allow",
    "Principal": {
        "Service": "budgets.amazonaws.com"
     },
    "Action": "SNS:Publish",
    "Resource": "your topic ARN"
}

Hope it works!