Yes, Twilio does not provide "dial tone" to your phones but we do let you build applications on top of them. Twilio can receive calls from or place calls to any phone with a phone number, such as land lines, cell phones, and VoIP phones. Additionally, Twilio can receive text messages from and send text messages to any phone number that supports SMS, such as mobile phones.
Twilio can provide phone numbers in nearly every area code in the US and Canada, as well as North American toll free phone numbers. Twilio phone numbers are not yet available in other countries.
When your account balance reaches zero you will no longer be able to make/receive phone calls or text messages, but you won't lose your phone numbers right away. We know that sometimes your Twilio account could be depleted because your credit card expired or you forgot to recharge. If that happens We will continue to bill your account for 90 days with the monthly charges for holding on to any phone numbers associated with that account. To reclaim your account and numbers, simply pay off your balance and fund your account with a minimum of $20. After 90 days, if you haven't paid your Twilio account, we may close your account and revoke your phone numbers.
Twilio supports calling to thousands of international destinations around the world, but international calling is disabled for trial accounts. Click here to see US/Canada pricing and here to see rates to other countries. See our International FAQ for more details.
After you upgrade your account, your applications can call to thousands of destinations worldwide. However, since you may not want to enable end-users to make more expensive international calls, we have a permissions system that lets you enable or disable calls to particular areas. Click here to see international pricing and click here to view the permissions dashboard for your account.
Trial accounts are not able to make international calls in order to protect against fraud. However, if you have a specific application in mind and would like to turn on international calling for your trial account please contact support and we will be happy to help.
In order to protect against shenanigans, if you want to use a non-Twilio provided phone number as your CallerID on outgoing calls, you must validate that phone number first. Validation takes just a minute, and proves to us that you own the phone number you wish to use as caller-id. Sorry frat boy, no prank calls from your bro's phone number.
Adding a validated caller ID to your account allows you to specify a caller ID that will appear on call recipient's phone that is different from your Twilio number. To validate new numbers, log into your Twilio account and visit the [Phone Numbers][[phone-numbers] section. Scroll to the bottom to add new Caller IDs.
International caller IDs must be manually added to your Twilio account. Please email support with the international phone number you want to add as a caller ID, and we will be happy to help you set this up.