There are strict rules for a property rental business to qualify as furnished holiday lettings. The most important conditions are:
For individual landlords the 210 day and 105 day tests apply to the tax year or the first 12 months on commencement of the rental business.
If the 105 day test is not met it is possible to make a “pooling” or averaging election where several FHL properties are rented out in the tax year. You can elect to apply the letting condition to the average rate of occupancy for all the properties you let as FHLs. There are separate elections or pools of UK and EEA properties.