A phone number can be used for phone verification at most 3 times.
This means that if you have 3 OpenAI accounts, you can use the same number to complete phone verification each time an initial API key is generated for these three accounts.
For fraud prevention and abuse prevention reasons, it is not permitted to unbind a phone number in order to release it for reuse, and deleting an OpenAI account will not release the number to bypass this restriction. There is no other way.
No exceptions are provided for this rule. It is recommended that you try using another phone number or access a previous account associated with your phone number.