LONDON (AP) — Sam Schwarzkopf, a German neuroscientist at University College London, was startled to receive a letter from the British government telling him that his application for permanent residence had been rejected and he should prepare to leave the U.K. The number of residence cards issued by the British government shot up sevenfold between the final quarter of 2015 and the same period in 2016. Applicants have to fill out an 85-page form and supply reams of supporting documents including pay slips, bank statements and proofs of address. Like him, other rejected applicants have been sent government letters telling them to prepare to leave the country they call home. Following complaints from Schwarzkopf and others, the Home Office says it has changed the wording of its refusal letters "to make clear that nobody who has the legal right to remain in the country has to leave the country." Some applicants have fallen foul of a requirement that people who are not employed or looking for work, such as students and full-time parents, must prove that that they had "comprehensive sickness insurance" while living in Britain. EU countries also have agreements that guarantee citizens can get medical treatment in other member states. Oxford University PhD student Dora-Olivia Vicol said she spent weeks trying to get a document from her homeland, Romania, to prove she had health coverage. Jonathan Portes, a professor of economics and public policy at Kings College London, said the system is "a complete mess."