People come to the United Kingdom for a wide variety of reasons, including to work, to join family members, to go on holiday, to study, or to seek asylum.

The rules determining access to free NHS treatment are complex, and depend on both the type of service and a person’s immigration status.

Some services, such as GP services and treatment in an A&E department, are free of charge for anyone, regardless of how long they have been in or intend to stay in the United Kingdom.

Free access to other types of NHS-provided hospital care depends on immigration status. There are slight differences in the rules between England, Scotland and Wales, but in general people can receive NHS hospital treatment without charge if:

• they qualify as ‘ordinarily resident’ in the United Kingdom. The 2014 Immigration Act tightened the definition of ’ordinarily resident’ as it relates to NHS services by linking it to an individual’s right to 'indefinite leave to remain' in the United Kingdom. Indefinite leave to remain can only be applied for after a minimum of five years’ residence in the United Kingdom
• the United Kingdom has a reciprocal health care agreement with their country of residence. People who are not defined as ‘ordinarily resident’, such as temporary migrants and visitors, can claim treatment on the NHS if their country of residence has a reciprocal agreement. This includes, for example, all European Economic Area-residents (comprising all of the European Union plus Iceland, Liechtenstein and Norway). For these European Economic Area citizens, the United Kingdom can subsequently recoup the costs of treatment from their respective governments.
• they fall within one of a range of specific groups, eg, if they are making an application for asylum in the United Kingdom.

There has been a great deal of debate about the impact of immigration on the NHS. However, there is a lack of reliable data on the use of health services by immigrants and visitors – most routine data sources do not record the information necessary to make a robust estimate. This is not an issue limited to the use of health services by immigrants: the use of GP and community services by UK residents is not routinely recorded, let alone the use by immigration status.

The best research on this is, by its own admission, tentative. The Department of Health published research into the cost of providing services to visitors and immigrants in 2013. The total gross cost at the top end of the estimate is £2 billion per year, of which a relatively small amount was recouped through charges and other arrangements. However, this total includes the use of the NHS by nationals of countries with which the United Kingdom has a reciprocal agreement. Within this total, ‘health tourism’, where people come to the United Kingdom with the express intent of using health services to which they were not entitled, was estimated to cost between £60 million and £80 million per year. This compares to the annual NHS budget of £113 billion.

The average use of health services by immigrants and visitors appears to be lower than that of people born in the United Kingdom, which may be partly due to the fact immigrants and visitors are, on average, younger. All these estimates exclude those who qualified as ‘ordinarily resident’ at the time and so do not include many people that might be referred to more widely as ‘immigrants’.

The rules for immigrants and visitors are already changing. Alongside the change to the definition of ’ordinarily resident’, the Immigration Act 2014 (which came into force in April 2015) requires temporary residents from outside the European Economic Area entering the United Kingdom for more than six months to pay a surcharge prior to entry in order to access the NHS for free. Prior to these changes, the United Kingdom tended to be more generous in offering access to health services than many other countries.

The government has also announced steps to improve the recovery of costs of migrant and visitor health care. In July 2014 it announced that some patients from outside Europe using the NHS will be charged 150 per cent of the cost of treatment under new incentives for the NHS to recover costs from visitors and immigrants. It is also exploring recovering the costs of a wider range of services including from non-NHS providers of NHS care, pharmacy and dentistry.

The impact of immigration is not limited to use of NHS services. Immigrants can also work in the NHS. According to figures from the Health and Social Care Information Centre, 20 per cent of the NHS workforce is non-British as of September 2014. This rises to 30 per cent of doctors, when locums are included. According to figures from NHS Professionals, over and above this non-British staff also account for a significant proportion of agency staff working in the NHS, as approximately 31 per cent of nursing shifts covered by agency staff over the past year were worked by foreign staff on temporary visas.