What are the limits on outbound calls and SMS messages per-second?
By default each Twilio account can make 1 outgoing call per-second. If your account needs more, please contact our sales team about options for higher limits.
SMS via Long Code
Each Twilio SMS-enabled long code (regular 10 digit number that excludes toll free numbers) can send 1 SMS message segment per-second, per-number. Unfortunately we are not able to adjust this rate limit. If your application requires a high volume of outgoing SMS, we recommend using an SMS short code.
SMS via US or Canadian Toll Free Long Code
US and Canadian toll free phone numbers have a rate limit of 3 message segments per-second, per-number.
For more details, please read “How quickly can I send SMS messages“?
SMS via Short Code
Inbound Calls and SMS
Twilio places no limitation on the rate at which a number can receive inbound calls or SMS messages. That said, if you expect to be receiving a huge amount of traffic, it doesn’t hurt to let us know in advance so we can help you to optimize your application for the increased traffic.