80601: Phone Number Not Available

This warning appears when the Twilio phone number you are trying to use is not available for the requested Proxy operation. In Proxy, a Twilio number can belong to only one Proxy Service at a time, and any number you set as a participant's ProxyIdentifier must already be added to that service's phone number pool.

• The Twilio number is already associated with another Proxy Service, so it cannot be used in a second Proxy number pool.
• You specified a participant ProxyIdentifier, but that number has not been added to the target Proxy Service phone number pool.
• The number is still being kept in a Proxy pool while existing participants drain, so it is not yet ready to be removed or reused somewhere else.

• Check whether the number is already attached to another Proxy Service. If it is, remove it from that service before you try to use it in a different Proxy service.
• If you want to assign a specific ProxyIdentifier, add that Twilio number to the same Proxy Service first by creating a Proxy PhoneNumber resource.
• If you are moving a number out of a pool, mark it as Reserved and wait until no active participants are using it before you remove or reassign it.
• If your application needs more available numbers for active sessions, add more Twilio numbers to the Proxy phone number pool and size the pool to match your session volume.

• Phone Number resource for Proxy
• Phone Number Management for Proxy
• Reserved Phone Numbers