DOCTORS must sign a new register - or they will not be allowed to work in this country.
The scheme, launched by the General Medical Council (GMC), aims to make sure GPs are fit to practise.
And for the first time, employers and patients will be able to see which doctors are eligible to work as GPs in their area.
The register was launched by the GMC, which already licenses doctors to practise in Britain.
The only doctors who will not have to sign up are doctors in training, such as GP registrars.
People can check on their doctors by logging on to the GMC's website at www.gmc-uk.org.
The GMC has worked with primary care trusts across the UK to set up the register.
Stephen Brearley, chairman of the GMC's Registration Committee, said: "This is an important step, giving qualified GPs the opportunity to be easily recognised as such by the public and employers."
Jane Kennedy, the minister in charge of delivery and quality in the Department of Health, added: "Patients can be assured that doctors on the register meet the standards and requirements to work in the NHS, wherever they were trained."
* Doctors who have not yet registered can get on the list by emailing email@example.com.