Jointly owned holiday lets: the 50:50 default and form 17

One property business, several properties

Two further points from the same guidance change how co-owners should think about their numbers. First, your share of a jointly owned property business is not a separate business from any properties you may own yourself. The shared cottage and your own flat sit inside one UK property business. Second, if you let more than one property, the profits and losses are added together to arrive at one figure of profit or loss — so a loss on the cottage can absorb profit from the flat. UK and overseas properties, however, must be kept separate.

That aggregation is why co-owners who each keep their own spreadsheet often arrive at the wrong answer. The figure that goes on a return is not "my half of the cottage". It is the whole UK property business.

Records, because two owners means two sets of paperwork

With co-owners, the practical failure is duplication and gaps: one owner claims the boiler service, the other claims it too, and nobody has the invoice. Our advice is unromantic. One bank account for the property, one place where invoices land, one shared record of nights let and income received, and a single annual pack that both owners give their advisers.

What to do this year

• If you are married, in unequal shares, and entitled to income in those shares, ask an adviser whether form 17 is worth filing and what evidence you hold.
• Consolidate the bookkeeping into one record, not one per owner.