Using Twilio SMS API, can I specify multiple destination phones in one post?

Question

Twilio limits long code SMS to 1/sec. To improve my throughput, I split my batch into 5 phone numbers. I\'ve found each HTTP POST to the Twilio API takes about 0.5 seconds.

Answer 1

Twilio Evangelist here. At the moment, we require that you submit each outgoing SMS message as its own API request.

The current rate limit on a longcode is 1 message per second. If more messages per second are sent, Twilio queues them up and sends them out at a rate of 1 per second.

A potential workaround is to make async requests across multiple phone numbers. This can be accomplished with the twilio node.js module or an evented framework such as EventMachine for Ruby or a similar toolset for your language of choice.

Hope this helps!

Answer 2

Here's a more modern answer. Twilio now supports Messaging Services. It basically lets you create a service that can group multiple outbound phone numbers together. So, when you fire off requests for a text to be sent, it can use ALL the numbers in the message group to perform the sending. This effectively overcomes the 1 text per second limit.

Messaging services also comes with Copilot. It adds several features such as "sticky sender". This ensures the same end user always gets texts from the same number in the pool instead of getting a text from different numbers.

Answer 3

If you are using the trial account, even looping with a 5s timeout between each item in the array did not work for me. And that was for just two numbers. Once I upgraded the account the code worked immediately without needing a timeout.

You know it's the trial account if the SMS you receive (when sending to only one number) says "Sent from your Twilio trial account - ".