Föhr’s unified municipal Kurabgabe is €3.50 per person per day during the main season (1 March–31 October) and €1.80 per person per day during the rest of the year. For overnight stays, the arrival day counts as a full day and the departure day does not. A voluntary or owner-related annual flat rate is €105.00. Children on group trips or children travelling without an adult supervisor pay €0.50 per person per stay day year-round.
Exemptions include people with a documented disability requiring constant assistance and, when staying in the same accommodation, their accompanying person; children and young people under 18 when accompanied by an adult supervisor (children on group trips or without adult supervision instead pay €0.50/day); people present for work or business on behalf of a locally based client who do not use municipal spa/recreation facilities or events; qualifying relatives hosted free of charge in the household of a resident, provided they do not use those facilities or events; and Amrum day visitors with a valid Amrum guest card staying on Föhr for no more than one calendar day. Non-resident owners of holiday homes are not generally exempt: they owe the €105 annual Kurabgabe instead.
The official sources do not identify a separate municipal registration-number scheme or a general Zweckentfremdungsverbot by that name. They do require holiday accommodation to comply with applicable planning/building law: the City of Wyk says holiday apartments may require lawful planning status or a building/use permit, and unapproved holiday use may be prohibited; owners are directed to the Amt Föhr-Amrum building authority or the district of Nordfriesland. For the Kurabgabe, every accommodation provider (including an owner who hosts relatives or friends free of charge) must issue the guest card, collect and remit the charge, and use either the electronic or paper registration-certificate procedure. Changes to the provider’s person or address must be reported in writing within two weeks; guest records must be retained for at least three calendar years. The Satzung’s required data include the property address, host name and the host’s Betriebsnummer.