Your NHS number isn’t random. It has a built-in checksum. That’s a fancy math trick to prevent typo errors. The last digit is basically a bouncer checking ID for all the other digits.
If you ever try making up an NHS number (don’t do that, obviously), the system will know instantly. It’s like trying to fake a VIP wristband at a rock concert. The bouncers are ruthless.
Also, the number never changes. Even if you move to the moon, you keep the same one. It’s more loyal than most of your exes.
