Starting February 2016, Twilio’s Terms of Services was updated to include the following number utilization requirements:
You agree that the following minimum usage and call duration requirements, to be measured at the master account level on a calendar month basis, apply to your use of the Services:
- At least two (2) transmissions, which transmissions may be in the form of an inbound or outbound call, or SMS message.
- No more than 10% of your outbound voice calls may be under twelve (12) seconds in duration.
- No more than 10% of your inbound toll-free voice calls may be under twelve (12) seconds in duration.
- No more than 10% of your inbound toll-free calls may be incomplete (i.e. unanswered).
Twilio sets a minimum usage requirements because phone numbers are public goods that are a in limited in quantity. Because adding new area codes/prefixes and overlays is expensive to implement and unpopular with voters, regulators in various countries (especially in United States) are increasingly reviewing number utilization and advising on a minimum usage to discourage the behavior of idle phone numbers.
When the defined requirements are not reached, regulators have the right to reclaim the phone numbers back from Twilio (however, this happens in rare cases), and thus releasing the number(s) from your ownership. To prevent losing your numbers under these circumstances, Twilio encourages you to make the most use of your phone numbers. Below are some general guidelines:
- It’s important to buy numbers that you will use, not numbers that you might use. There are a few reasons you may create an inventory (limit competition, quick roll out to employees/customers), but you may also be limiting access to partners, developers, and customers in those areas that benefit your business or innovations. It’s not cool to sit on phone numbers without using them, and could cause regulatory problems.
- But it IS cool to release unused numbers back to Twilio if you realize you have a surplus. Releasing back phone numbers is free of charge and also saves you from paying the recurring monthly fees.
- If your use case requires assigning numbers to your customers, see if you can improve your inventory management. For example, check your phone numbers regularly, and if you see a number that's not used, reclaim it back from your customer and reuse it somewhere else. Twilio performs a similar action by reclaiming unused (and unloved!) phone numbers in trial accounts on a regular basis.
- If your use case requires that you cycle through multiple phone numbers, re-use your numbers wherever possible, rather than releasing it and buying a new one.
- Consider “pooling” your numbers so that you get the most out of them. For example, Twilio’s Messaging Copilot embraces a number pooling concept that allows you maximize the use of your phone numbers without working on your own application logic.