What is the Throughput Limit for Outbound SMS?


  • What is the throughput limit for Outbound SMS?
  • Is there a rate cap for outbound SMS?
  • How fast can I send Outbound SMS?
  • What happens if I exceed the throughput limit?


All API keys are set with 30 API request per second throughput restriction by default. On top of this, there are also restrictions when sending from certain numbers, such as sending using a US long virtual number. When sending from US long virtual numbers, you are restricted to 1 SMS per second. You can check country specific restrictions in Country Specific Features and Restrictions

We recommend our customers to implement throttling mechanism, or API requests will be rejected with status code 1 - Throttled.

We also support higher throughput when needed for resellers, large senders of SMS and for specific campaigns, so please contact your account manager if you would like access to higher throughput volumes and we will review on a case by case basis.

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