Amazon Simple Notification Service (SNS) | Limits and Restrictions

Question 1

Is there a ‘free tier’ allowance for SMS messages?

Limits and Restrictions

Amazon Simple Notification Service (SNS) | Application Integration

Answer 1

There is a monthly free tier allowance for SMS messages. The first 100 SMS messages sent to US phone numbers each month are free. Additional SMS messages to the US or any messages sent to non-US phone numbers are charged based on current pricing provided here.

Question 2

Are there limits to the number of topics or number of subscribers per topic?

Limits and Restrictions

Amazon Simple Notification Service (SNS) | Application Integration

Answer 2

By default, SNS offers 10 million subscriptions per topic, and 100,000 topics per account. To request a higher limit, please contact Support.

Question 3

How much and what kind of data can go in a message?

Limits and Restrictions

Amazon Simple Notification Service (SNS) | Application Integration

Answer 3

x9 | #xA | #xD | [#x20 to #xD7FF] | [#xE000 to #xFFFD] | [#x10000 to #x10FFFF]

With the exception of SMS messages, Amazon SNS messages can contain up to 256 KB of text data, including XML, JSON and unformatted text.

The following Unicode characters are accepted:

(according to http://www.w3.org/TR/REC-xml/#charsets).

Each 64KB chunk of published data is billed as 1 request. For example, a single API call with a 256KB payload will be billed as four requests.

SMS messages

Each SMS message can contain up to 140 bytes, and the character limit depends on the encoding scheme. For example, an SMS message can contain:

160 GSM characters

140 ASCII characters

70 UCS-2 characters

If you publish a message that exceeds the size limit, Amazon SNS sends it as multiple messages, each fitting within the size limit. Messages are not cut off in the middle of a word but on whole-word boundaries. The total size limit for a single SMS publish action is 1600 bytes.

Question 4

How many message filters can be applied to a topic?

Limits and Restrictions

Amazon Simple Notification Service (SNS) | Application Integration

Answer 4

By default, 100 filter policies per account per region can be applied to a topic. Please contact us if more is required.