You will need a commercial mortgage to fund serviced accommodation - a standard buy-to-let mortgage isn’t suitable.
Buy-to-let mortgages are designed for properties that are rented out for long-term periods, at least six months on an AST.
A serviced accommodation mortgage may have a restriction on the maximum amount of time your property can be let to the same occupier, so you’ll need to be aware of any conditions when marketing your property.