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".

Article contents:

• MMS Rate Limiting for Long Codes
• MMS Rate Limiting for Toll-Free numbers
• MMS Rate Limiting for Short Codes
• Recommendations

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: A rate limit on each Twilio Account (parent account and all subaccounts) 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 (Parent Project and all Subaccounts)	50
Twilio US & CA long code number	1

Examples:

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 75 Twilio long code phone numbers on their account would have a maximum rate of 50 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 50 MPS throughput for long code MMS at all times – 50 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 Toll-Free numbers

Similar to long code numbers (described above), Toll-Free MMS throughput (MPS) is limited at the per-phone number level, as well as per Twilio Account SID.

Each Toll-Free number has a default throughput of 3 MMS per second. If you have a High-Throughput Toll-Free number with greater than 3 MPS for SMS, this increases your MMS throughput as well, up to 25 MPS for that specific Toll-Free number.

However, each Twilio Account SID is also limited to 25 MMS/second from all Toll-Free numbers on that Account SID. This is a separate limit from the long code number MMS limit described above.

Toll-Free MMS limit type	MMS Messages per Second (MPS)
Twilio Account (Parent Project and all Subaccounts)	25
Twilio US Toll-Free number	3 (or up to 25 with High-Throughput Toll-Free - contact Sales for details)

For example: If you have a Toll-Free Twilio number which you have increased to 50 MPS for SMS, you will have 25 MPS for MMS via that number. If you have a second Toll-Free Twilio number with 25 MPS for SMS, it will also have 25 MPS for MMS. However, the two numbers combined will be able to send at 25 MPS at any given moment. Messages will be queued if you exceed 25 Toll-Free MPS across your Twilio account and any subaccounts.

Please note, using multiple Toll-Free numbers is not recommended unless there is a specific business justification, e.g. multiple separate business locations that each require a dedicated number. For details, see Information and best practices for using Toll-Free SMS and MMS in the US and Canada.

MMS Rate Limiting for Short Codes

Twilio currently imposes a 50 MPS limit on short code MMS messaging. However, downstream carrier capacity may limit MMS throughput.

Additional resources

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.