Things break. When you pay to put business property or equipment back in working order, that is a repair you can claim in full. When you pay to make something better than it was, that is capital — and HMRC treats the two very differently at year end.
What you can claim
Repairs to business premises — fixing a leaking roof, mending a boiler, repainting worn walls.
Maintenance on tools and machinery — servicing, sharpening, safety checks.
Replacing broken parts — a new pump for the pressure washer, a fresh belt for the lathe.
Like-for-like replacements — swapping a dead appliance for a similar model.
Ongoing upkeep — decorating, gutter clearing, pest control.
Essential safety checks — gas safety certificates, electrical inspections, PAT testing.
Landlords' replacement of domestic items — cookers, sofas, beds — on a like-for-like basis.
What you can't claim
Improvements — building an extension, installing a brand-new kitchen, upgrading to a bigger, better machine. These are capital costs.
Buying equipment for the first time — a new van or lathe is capital expenditure, not a repair.
Repairs to your home — unless a room is used for business, in which case only that share.
Work done before you owned or started trading — initial repairs to bring a property up to scratch are capital.
Old-style wear and tear allowances — abolished in 2016 for furnished lettings, replaced by the replacement of domestic items rules.
Common mistakes
The repair-or-improvement line causes the most debate. Replacing a knackered boiler with the same class of boiler is a repair; building a conservatory is not. When a job mixes both — reroofing and adding skylights, say — ask your contractor to split the invoice, and record it with a note explaining what was done.
The second mistake is parking major purchases here to avoid thinking about capital allowances. A £3,500 woodworking machine is not a repair, and a large "repairs" figure in your quarterly totals is exactly the sort of thing that gets queried.
Landlords make the mirror-image error: claiming the initial furnishing of a flat as a "replacement". Only like-for-like replacements count — the first sofa is capital, the second one (when the first wears out) is claimable.
How to record it in your MTD tracker
Select Repairs and renewals and note what was repaired and where. If the work looks like an improvement, still keep the receipt but flag it for your accountant — it may need to go through capital allowances instead of your quarterly expense totals.
Track all your expenses in HMRC's own categories with the MTD Sole Trader Tracker.