Smart Queueing
Smart Queueing keeps your messaging traffic within each carrier's rate limits, so you get the highest throughput available without messages failing or getting capped early.
Central to this is registering your traffic with The Campaign Registry (TCR). TCR registration unlocks higher throughput, and Smart Queueing is what actively manages it so you don't lose messages to carrier limits.
You don't need to configure or monitor anything. Smart Queueing runs automatically for all 10DLC and toll-free traffic, free of charge.
Throughput limits
Throughput limits, also called rate limits, cap how many messages (SMS segments and MMS messages) you can send in a given window, usually expressed as TPM (throughput per minute) or TPS (throughput per second).
Limits vary by traffic type and by carrier. Extended vetting can raise your 10DLC limits.
Carrier | Limit |
|---|---|
AT&T | Independent SMS and MMS limits, typically per TCR Campaign (occasionally per Sender Phone Number). Example: 240 TPM for SMS, 150 TPM for MMS. |
T-Mobile | A cumulative daily cap for SMS and MMS, enforced per TCR Brand and reset at midnight Pacific time. Example: 2,000 messages per day. |
US Cellular | Independent limits per Sender Phone Number: 60 TPM for SMS, 20 TPM for MMS. |
Verizon | Independent limits per Sender Phone Number: 6,000 TPM for SMS, 25 TPS for MMS. |
Other carriers | A combined limit of up to 30 TPM for SMS and MMS per Sender Phone Number. |
Toll-free numbers get 180 TPM for SMS and 3 TPS for MMS per Sender Phone Number.
Throughput safety margin
We hold back a small safety margin below your actual TCR limit, to protect your traffic from carrier detection discrepancies and upstream incidents. We keep this margin minimal so you don't lose meaningful throughput. As of August 1, 2024, the margin is 10%, capped at 10 TPM.
Throughput alerts
We alert you when you're approaching your TCR throughput limit:
When you've used more than two-thirds, but not all, of your daily limit
When you've used the entire daily limit
If you're hitting these regularly, apply for extended vetting to raise your limits.
Message prioritization
Smart Queueing lets you prioritize messages so urgent ones go out first. A higher-priority message is always processed before lower-priority ones, regardless of when each was submitted. If a Campaign or Brand has mixed-priority messages queued, lower-priority messages wait until all higher-priority messages have sent and the limit resets. Configure the priority parameter on the Outbound Message with either Urgent, High, Normal, or Low.
Time routing
Time routing controls when queued messages actually go out.
Sending times: set allowed sending windows in your messaging configuration. Delivery pauses outside those windows.
Message expiration: set an expiration time on individual messages with the ExpiresOn field on the Outbound Message endpoint. If a message doesn't send before it expires, its status changes to Expired and we stop attempting delivery.
Limit: The maximum expiration period is 72 hours from the time you submit the message.