What is a subaccount?
A subaccount is an account that rolls up to your parent Twilio account. It allows you to separate your account’s phone numbers, usage, and application settings. All billing for subaccounts rolls up to the master account, but you can pull usage logs on the subaccount level so you could, for example bill a client or an internal department for the usage on that account.
By default a master account can only have 1000 subaccounts. Closed subaccounts do not count towards this limit. If your account is approaching 1000 subaccounts, contact Twilio Support to ask about raising this limit.
For more information on subaccounts, see our subaccount documentation.