API Rate Limiting

To protect the platform from being overloaded and maintain a high quality of service to all customers, 8x8 enforces API rate limits for its SMS API.

The default request rate limit is 1800 HTTP requests per second per sub-account (can be adjusted upon request), and 3000 requests per second per IP address with no maximum daily quota.
All requests exceeding this quota will be rejected by the API with 429 Too Many Requests HTTP Status.

The API will also return the Retry-After HTTP header with the value indicating when the client can retry the request.

Retry-After: 1

In this example, you can retry the request after 1 second.



If you need to submit a higher volume of messages in bulk, please ensure to use the Send SMS batch API that allows you to submit up to 10,000 messages in a single API request, which currently is roughly equivalent to 25 000 messages per second.