Is it a repair or an improvement for landlord tax?

Is it a repair or an improvement for landlord tax? A repair puts back what was there, such as a broken boiler swapped for a similar one, and comes off your rent in 2026-27. An improvement adds or upgrades something, such as an extension, and is capital instead. Replacing a broken-down boiler is a repair. GOV.UK lists it as an example of a property repair, and its list of typical repair costs includes replacing existing boilers and radiators. Usually not. GOV.UK says replacing a single-glazed window with a double-glazed one is still a repair, as the nearest modern equivalent, where the improvement is incidental to the repair. HMRC's Business Income Manual says double glazing became the industry norm, so it stopped counting as an improvement. If it replaces the old one like for like, yes: GOV.UK lists replacing existing kitchens as a typical repair. Replacing a kitchen with one of a higher specification is one of GOV.UK's own examples of capital spending. Read the full answer, with every source, at rightotax.co.uk.