To purchase this number you must supply the Address of the user of this phone number. Previously the IncomingPhoneNumbers API would look at your account for an appropriate address, however, you are now required to pass in an AddressSid that satisfies the requirement for the phone number. This is because Twilio needs to know which address will be operating the phone number to meet regulatory requirements for that country and type of phone number.
Possible Causes
No address was provided
No address was that satisfies the locality requirement for this phone number type.
Depending on the country and number type, this may be an address in the same country or same geographic area as the number being purchased.
Possible Solutions
Add an address that satisfies the locality requirement.