Another option is to just fill out a registration form at the new GP surgery, give the name and address details of your old surgery (which it will ask for) and say that you have an NHS number, but you don’t remember it.
The new surgery should then request your medical records from the old surgery, along with your NHS number.
By the way, the way that you transfer from one GP surgery to another is by filling out a registration form at the new GP... and they will do the rest for you.
Sent from my iPhone using Tapatalk