IntelePeer's SMS Rate Limits and Message Queue Guidelines

At IntelePeer, we follow regulatory and carrier best practices on SMS quota regulations to ensure your messages are successfully distributed.

What are IntelePeer's Guidelines on Throttling?

IntelePeer is aligned with the Cellular Telecommunications and Internet Association (CTIA) in regard to message throttling. While voluntary, these restrictions can have delivery implications customers should be aware of. To help keep you in compliance, we automatically queue your messages and deliver them to the carrier at an appropriate throughput rate. These guidelines are to help ensure messages are not blocked by wireless carriers due to spam filters. IntelePeer cannot guarantee the wireless carriers will not block messages even if guidelines are followed.

What is Throttling?

Throttling refers to controlling your SMS traffic. This can be with regards to throughput or velocity of concurrent messages sent per number per minute, the volume of messages sent per number of days, the number of unique recipients, and the balance or ratio of outgoing to incoming messages per number. Throttling helps you manage the timing of your messages, which can be important, especially when you’re expecting a large response back.

Limits by Traffic Type

Person-to-Person (P2P), generally describes the low volume exchange of wireless messages between mobile end users. This type of traffic must be consistent with typical human operations to distinguish P2P from A2P (Application-to-Person) traffic. P2P traffic is typically done via Long Code/DID, for example, unspecified conversations between two mobile end users, surveys, and group messaging are considered to be P2P messaging.

Sending Limits Per Type

Use the following information to understand the sending limits for each sending code type:

Sending Code Type

Sending Speed
Long Code 1 every 2 seconds
Toll-Free 10 per second
Alphanumeric 10 per second
Short Code 10 per second

For P2P Traffic, or Traffic Associated with a Long Code/DID:

  • Message Volume is not restricted by IntelePeer but recommended to be no more than 300 messages per day per number based on CTIA guidelines

  • Unique Recipients is not monitored by IntelePeer but recommended to be 200 distinct recipients per number based on CTIA guidelines

  • Message Balance is not throttled by IntelePeer but recommended to be near a 1:1 ratio of MT to MO (Mobile Termination outbound to Mobile Origination inbound) messages based on CTIA guidelines

Application-to-Person (A2P) is all traffic not consistent with typical human operation. The messages may be sent from an application to a mobile end user and includes, but is not limited to, marketing messages, appointment reminders, announcements, and banking alerts. Receiving a text from your favorite airline about your upcoming flight details is an example of A2P messaging.

For A2P Traffic, or Traffic Associated with a Toll-Free Number (TFN):

  • Message Velocity throughput is throttled by IntelePeer at a rate of up to 10 MT outbound messages every one second
  • Message Volume is not restricted
  • Unique Recipients is not monitored by IntelePeer
  • Message Balance is not throttled

Note: While IntelePeer releases messages to our carrier partners at these rates, your messages may be subject to wireless carrier filtering and can get blocked by the wireless carriers. Keep in mind your unsent messages are not lost; we buffer and queue messages to be sent. In aligning with CTIA best practices with respect to traffic, we implement a 1,000 messages buffer size per DID. For toll-free numbers (TFN), we implement a 10,000 messages buffer size. If you exceed the available buffer, the API denies your send-request with an error message until space becomes available. We support a maximum rate of 25 API calls per second per Customer and each message sent uses a separate API call.

Disclaimer: IntelePeer customers are responsible for compliance with all privacy laws. Even though CTIA guidelines are voluntary, there are still repercussions, such as messages being blocked by wireless carriers due to spam filters. This means you may incur the cost of sending messages that are not received by your end customers. Numbers can become blocked or even blacklisted. IntelePeer recommends you consult an attorney to confirm your text messaging campaigns conform to all applicable laws.

Note: Wireless providers may block messages without recourse

Learn More

Check out the following links for information on regulations and best practices: