BT port numbers on request, AFAIK, it’s not really possible to refuse, ‘ officially ’ number portability should be a reciprocal arrangement, so if a company ‘imports’ numbers from others , they also should be able to export numbers in the same way , on request, BT to a VoIP provider is something frequently done and the VoIP provider , considering pretty much their entire business is built on being able to import numbers from others , should be proficient in the process.
