Every spring the same hunt: gathering valuation notices, tenancy agreements and purchase deeds to work out what belongs in box 3. RealGrip keeps it per property, works out the occupied-value ratio and the return, and follows the rules as they change.
Record the official value with its reference date per property. If it is let, RealGrip determines from the annual rent which occupied-value ratio applies and what the value in let condition becomes. No side calculation in a spreadsheet you cannot find again next year.
Rental income and costs come from the books you already keep, so the return per property follows by itself. Loans count as debt. You see not only what the tax office wants to know, but also whether a property really earns what you assumed.
Rates and flat amounts change. RealGrip checks each quarter what has changed in the rules and prepares a proposal with its source. It is applied only after an administrator approves it — because a wrongly copied percentage works its way into every return.
Box 3 is part of FinPro, the rental bookkeeping inside RealGrip. What you record through the year is ready when the return is due. RealGrip provides figures, not tax advice — the return stays yours or your adviser's.