Anybody in England can register with a GP practice and receive free medical care from that practice.
However if you are not 'ordinarily resident' in the UK you may have to pay for NHS treatment outside of the GP practice. Being ordinarily resident broadly means living lawfully in the UK on a properly settled basis for the time being. In most cases, nationals of countries outside of the European Economic Area must also have the status of 'indefinite leave to remain' in the UK.
Some services,such as diagnosis tests of suspected infectious diseases and any treatment of those diseases are free of charge to all people, while some groups who are not ordinarily resident here are excempt from all treatment charges.
You maybe asked to provide proof of entitlement in order to receive free NHs treatment outside of the GO practice, otherwise you maybe charged.
The information you give on this form will be used to assist in identifying your chargeable status, and maybe shared, including with secondary care organisations.