There are limits to how quickly MMS messages can be sent to wireless carrier networks. This guide explains how Twilio processes your MMS message requests, and any associated rate limitations.
Notice: Similar to SMS, you can send MMS message requests to Twilio at a rapid rate, as long as the requests do not max out Twilio's REST API concurrency limit. When this concurrency limit is reached, Twilio will begin responding to your requests with
HTTP 429, or Error code 20429. For more information, see Twilio API response Error 429 "Too Many Requests".
MMS Rate Limiting for Long Codes
Twilio has two types of rate limits for sending long code MMS messages: long code phone number level and Account SID level.
- Long code phone number: A rate limit on each Twilio long code phone number to keep you in compliance with carrier regulations, and reduce your risk of filtering.
- Twilio Account SID: A rate limit on each unique Twilio Account SID (project or subaccount) protects our network performance, and helps to ensure fair service across all customers.
Below is a quick summary of the maximum rate limits for long code MMS:
|Long Code limit type||MMS Messages per Second (MPS)|
|Twilio Account SID (Project or Subaccount)||25|
|Twilio US & CA long code number||1|
Long code phone number rate limit: A customer with a total of 8 Twilio long code phone numbers on a single Account SID would have a maximum rate of 8 long code MMS messages per second.
Twilio Account SID rate limit: A customer with a total of 30 Twilio long code phone numbers on a specific Account SID would have a maximum rate of 25 long code MMS messages per second.
Notice: These rate limits describe the maximum rate at which long code MMS messages will be processed and sent to carrier networks. This is not an SLA for delivery speed. Twilio does not guarantee 25 MPS throughput for long code MMS at all times – 25 MPS is a maximum, and average throughput may differ. Multiple factors, including traffic congestion, downstream carrier issues, and individual device behavior, may impact the actual delivery speed.
MMS Rate Limiting for Short Codes
Twilio currently does not impose a rate limit on short code MMS messaging. However, downstream carrier capacity may limit MMS throughput at extremely high-volume sending.
- For time-sensitive messages, we recommend that you keep a close eye on the Message Queue length.
- Consider using multiple projects or subaccounts for different use cases, as well as multiple long code phone numbers.
- If you need higher than 25 MPS throughput for your MMS messaging, apply for a short code number.
For information about SMS message rate limiting, see Understanding Twilio Rate Limits and Message Queues.
If you have further questions, please reach out to the Twilio Support team.