Twilio · Rate Limits

Twilio Rate Limits

Twilio API rate limits enforce per-account concurrency on the REST API and carrier-imposed throughput limits on messaging products (e.g., A2P 10DLC TPS).

5 Limits Throttle: 429
Rate LimitingCommunications

Limits

REST API concurrent requests account
concurrent
100
Default per-account concurrency; raise via support.
Messaging A2P 10DLC throughput (T-Mobile) campaign
messages_per_second
75
Varies by brand vetting score and campaign trust score.
Messaging Toll-Free number
messages_per_second
3
Verified Toll-Free Numbers can request higher TPS.
Messaging Short Code short_code
messages_per_second
100
Default; can be increased via carrier vetting.
Voice concurrent calls account
concurrent_calls
1
Trial accounts; production accounts default to higher limits.

Policies

Carrier Filtering
Beyond Twilio rate limits, destination carriers enforce their own throttling and content filtering.
Queue and Retry
Twilio queues outbound messages exceeding TPS for up to 4 hours by default.
Geographic Permissions
Voice and SMS to specific countries must be enabled on the account before sending.

Sources