I believe some cities have even more codes. Or maybe their codes are not 3 digits but 4 or 5. 3-digit code is not enough to cover huge megalopolises. I may be wrong, and such a thing should be checked on official cites
https://dialcodes.co.uk/areacodes/0151. The code system can be updated regularly in view of the growing population and territory. So if you haven’t checked your area code recently, verify it.