What is 90-Day Rule?

The 90-day rule is a regulatory cap adopted by several major cities to limit the number of nights per year that a property can be rented out short-term. London caps it at 90 nights, Paris at 120, and Amsterdam at 30. In London, a host who exceeds 90 nights per year without planning permission is breaking the law.

The intent behind the cap is straightforward: let homeowners earn supplemental income while preventing the permanent removal of housing stock from the long-term rental market. Platforms like Airbnb in some cities automatically delist properties once they hit the cap, though workarounds and multi-platform listings make enforcement difficult.

Why It Matters When Choosing Where to Live

The presence or absence of a night cap in your target city directly affects how much short-term rental activity you will encounter. In cities with strict caps and active enforcement, buildings retain more of their residential character because hosts cannot operate year-round. In cities without such limits, or where enforcement is weak, there is nothing stopping a neighbor from running a full-time tourist operation next door.

Even in cities with the rule, not all hosts comply. Knowing whether your city enforces its night cap, or just has one on paper, gives you a realistic picture of what to expect.

How BnBDetector Helps

A BnBDetector scan shows the intensity of STR activity around your address. If your building shows year-round rental patterns in a city with a 90-day rule, that is a sign hosts are exceeding the limit, and enforcement is not keeping up.