Put a repair, a fee or a bill against a property so it counts at tax time.

On a property's Finance tab, open the + menu and choose Add expense. Drop a receipt and we read the amount, date and vendor off it, or type them in. The picture above shows the form.
The category is the part that matters, because it decides how the cost is treated at tax time. Also track in account is optional and does not change your tax figures.
Putting back what was there — a boiler swap, redecoration — is a repair, and repairs reduce this year's tax.
Adding something that was not there before is capital, and capital is treated differently.
Not sure which category a cost belongs to? The expense catalogue lists them all and says, for each, whether it reduces this year's tax:

Most costs sit under Claim this year and lower your taxable profit automatically. A few — capital improvements, your own labour — are tracked for your records but do not reduce this year's bill.