Working From Home: What You Can Actually Claim

The flat rate

HMRC publishes simplified expenses: a flat monthly amount based on how many hours a month you work from home, in bands. You claim it without keeping any household bills at all.

It is genuinely simple and for someone working a few hours a week at the kitchen table it is usually the right answer. Check the current bands and amounts on GOV.UK, since they are set by HMRC and change.

The apportionment method

The alternative is to claim a fair proportion of your actual household costs: rent or mortgage interest, council tax, heating, lighting, and broadband where relevant.

The usual basis is rooms and time. Count the rooms in your home, excluding hallways and bathrooms, work out what proportion one room is, then apply the proportion of time that room is used for business. A spare room used exclusively as an office for a full working week produces a much larger claim than the flat rate.

Do not claim a room as 100% business use. It can affect the private residence relief position when you sell, and HMRC treats exclusive business use differently. Leaving some personal use is both more honest and usually safer.

Making it defensible

The apportionment method is not risky if your basis is sensible and written down. What makes a claim indefensible is a round number with no working behind it.

Record the calculation once: number of rooms, which one, hours per week, and the bills you apportioned. Keep the bills. If your circumstances stay the same, the same calculation carries forward, and if HMRC asks you have an answer rather than an argument.

Which to choose

Work out the apportioned figure once. If it is close to the flat rate, take the flat rate and save yourself the record keeping. If it is meaningfully higher, the paperwork is worth it.

You can also switch between years as your circumstances change. What you cannot do is claim both for the same period.