NO2ID

I was wondering how easy would it be to register with a GP under a false name and DOB but with a real address?

I understand this is not illegal since anyone living in the UK for 3 months is entitled to NHS treatment. It seems like a good possiblity for preserving privacy.

Would they be able to discover that you don't seem you exist? Would they ask for some kind of proof of ID or entitlement? Would it work at this moment in time but not in the future once the database systems become more joined up?

This wouldn't be easy.

If you're registering at a practise for the first time, they will want to know where you were registered previously, so they can apply to have your 'notes' transferred. Also you have an NHS serial number, which is linked to your name and DOB, so if you give false details, unless by some astronomical chance you pick someone elses, they're not going to be able to match you up with your NHS records, which could immediately cast doubt on the details you've given.

You could claim to have entered the country from abroad, but then they will almost certainly want to see your passport, so they can see that you are who you claim to be and that you're entitled to register. So (unless you have a false passport which is accepted as genuine) it would be very difficult to register with false details.

Look into the possibility of not registering at all, and seeking treatment as a walk-in when the need arises. AFAIK you are fully entitled to do this (so long as you are ordinarily resident in this country) but your GP won't like it as they lose the £75pa or so registration payment.

It is not illegal to be known by any name you like. A GP can decide for himself whether to register you as a temporary resident whether or not you are strictly entitled to treatment. If you really like your privacy, you'd be better off as a private patient if you can afford it.