When your project balance reaches zero, your account will become suspended. While suspended, you will no longer be able to make and receive phone calls or send and receive SMS messages.
Billing While Suspended
After your project has been suspended, Twilio will continue to bill your project for any phone numbers you have already purchased. If you don't intend to continue using Twilio services, or don't wish to keep these phone numbers, you can release your number(s) to stop the monthly recurring charges.
For more information about how numbers are billed to a suspended project, see Do I still get charged for phone numbers when my project is suspended
Notice: After 60 days of your project being suspended, your phone numbers are at risk of being reclaimed. Phone numbers not reclaimed will continue to bill as normal until they are released or removed.
Reinstate your Project
If your Twilio project becomes suspended due to zero or negative balance, you can manually add funds to refill your Twilio project. To prevent future suspensions due to balance, we recommend setting an automatic recharge trigger.