The U.K.’s National Health Service provides free, universal healthcare to U.K. residents. In the past, the NHS would provide treatment without knowing patients’ residency status, but new rules put in place in October mean that clinics now must ask for identity documents up front to determine whether patients must pay for care. The most recent U.K. Department of Health statistics suggest that health tourism costs the NHS £60-£80 million a year — less than a tenth of a percent of its overall budget. But it also says those figures are difficult to assess, because it’s hard to tell who is and is not entitled to free care.

Click the audio player above to hear the full story.