Two questions arrive together here. One is practical: which of the year's payments can be taken off rental income. The other is asked more often than it is answered honestly, because there is no way to avoid tax on rental profit that actually exists, only reliefs and allowances that reduce it and arrangements that do not work. This page gives the deductible list, the non-deductible list, and a plain account of which of the well-known ideas are real.
What comes off: the deductible list
Letting agent and management fees, advertising for tenants, accountancy for the letting, buildings and contents insurance, ground rent and service charges, council tax and utilities for periods you are liable, repairs and maintenance that restore rather than improve, the cost of replacing domestic items such as a bed or a sofa on a like-for-like basis, and the running costs of travel genuinely made for the letting. Each has to be incurred wholly and exclusively for the letting, so a cost that also serves you personally is either apportioned or refused.
What does not: capital and the personal share
The purchase price, legal and survey fees on acquisition, stamp duty, an extension, a loft conversion and any upgrade that leaves the property better than it was are all capital. They are not deductible against rental income, though they may reduce a capital gain when you sell, so they are worth recording rather than discarding. Nor can you deduct your own time, the capital element of a mortgage payment, or the private-use share of anything the property and you both benefit from.
The reliefs that are real
The property allowance removes small rental income from the reckoning entirely and can be taken instead of actual expenses where expenses are lower. The replacement of domestic items relief covers furniture in a let property. Losses carry forward against future rental profit from the same category, so a bad year is not wasted. The finance-cost tax reducer gives basic-rate relief on mortgage interest. None of these is a loophole; all of them simply require the claim to be made on the right year's return.
The ideas that do not work
Not declaring rent because it is paid in cash, or because the property is abroad, or because it is let to family below market rate, is not avoidance but a failure to report, and the lettings data HMRC receives makes it a poor bet. Transferring a property to a lower-earning spouse changes who is taxed but is a real transfer with real consequences, not a paper move. Incorporating a portfolio has genuine tax effects in both directions and is a decision for an adviser, not for a calculator. Where a question needs an adviser this site says so and stops.
Questions people ask about landlord expenses list
Can I claim for my own time managing the property?
No. Your labour is not an expense of the letting. Fees paid to a letting agent or a contractor are.
Is a replacement boiler deductible?
A like-for-like replacement is normally a repair and deductible. A first installation, or an upgrade to a materially better system, is capital.
Can I carry a rental loss forward?
Yes, against future profits of the same rental category. It is not set against your employment or trading income.
Does letting to family change anything?
Letting below market rate usually restricts the expenses you can claim to the rent received, so it cannot create a loss. The income still has to be reported.