It depends on how you use the property. Brighton & Hove City Council takes a case-by-case approach based on the degree of use change. Letting an entire home as a holiday let on a regular basis may constitute a material change of use (for example, to visitor accommodation or sui generis), which would require planning permission. Unlike London, Brighton has no citywide night cap, so there is no automatic threshold at which permission is required. If you are unsure, contact Brighton & Hove City Council's planning department before listing.