If you run part or all of your business from home, you are almost certainly incurring extra costs that the tax system lets you recover. Home office costs, often called use-of-home expenses, cover the heating, lighting, broadband and other running costs that go up because you work where you live. Whether you are a sole trader filing Self Assessment or a director running a limited company, claiming these costs correctly reduces your tax bill without inviting questions from HMRC. This guide explains the two methods available, how to apportion bills fairly, and the rules that differ depending on how your business is structured.
Why home working costs are claimable
The general principle is that an expense is allowable where it is incurred wholly and exclusively for the purposes of the business. Working from home blurs that line, because the same room is heated whether you are answering client emails or watching television. HMRC accepts this reality and provides practical ways to claim a fair proportion of household running costs, rather than expecting you to meter every kilowatt.
These costs sit alongside the wider category of allowable business expenses that you can set against your profits. Getting the home office element right is one of the most common questions for anyone working for themselves.
The simplified flat rate method
The simplest approach is the flat rate method, sometimes called simplified expenses. Instead of working out the exact share of each bill, you claim a fixed monthly amount based on the number of hours you work from home. The more hours you work, the higher the band you can claim.
The flat rate covers the running costs of working from home, such as gas, electricity and water used for the business. It does not cover broadband or telephone, which you can still claim separately on a business-use basis.
Benefits of the flat rate method include:
- Minimal record keeping beyond a log of hours worked at home.
- No need to retain every utility bill to support the running-cost claim.
- Speed and certainty, which suits freelancers with a straightforward setup.
The trade-off is that the flat rate is often lower than the figure you would reach by calculating actual costs, particularly if you work from home full time or have high energy bills. It is worth comparing both methods before you commit.
The actual cost method
The actual cost method involves working out the genuine business proportion of your household running costs. This usually produces a larger and more accurate claim, but it requires more effort and better records.
Typical costs you can apportion include:
- Heating and electricity
- Council tax
- Mortgage interest or rent
- Water rates, where business use is more than minor
- Home insurance
- Repairs and maintenance affecting the work area
You cannot claim the full bill. You claim only the share that relates to business use, calculated on a reasonable and consistent basis. In your books, the business share of heating, electricity and water is posted to utilities in the chart of accounts.
Apportioning bills fairly
A fair apportionment normally combines two factors: the proportion of rooms used for business and the proportion of time those rooms are used for work. Counting habitable rooms (excluding kitchens, bathrooms and hallways) gives you a sensible denominator.
| Step | What to work out | Example basis |
|---|---|---|
| 1 | Number of rooms used for business | One room out of six |
| 2 | Time that room is used for work | Business hours versus total waking hours |
| 3 | Apply both fractions to each running cost | Room share multiplied by time share |
| 4 | Sum the business portion across all bills | Total annual use-of-home claim |
The key is to be reasonable, consistent and documented. If HMRC ever asks, you want a clear calculation you can stand behind rather than a round number plucked from the air.
Rules for sole traders
As a sole trader, your home office claim reduces the taxable profit reported on your Self Assessment return. You can choose either the flat rate or the actual cost method, but you should apply your chosen approach consistently across the tax year.
Keep your home office figure in step with your wider bookkeeping. Our guides on sole trader bookkeeping basics and the self-employed and sole traders hub explain how these claims fit into your annual figures and Self Assessment.
Rules for company directors
If you operate through a limited company, the company and you as a director are separate from a tax perspective, so the mechanics differ. The two common routes are:
- A flat rate allowance. The company pays you a modest weekly amount to cover additional household costs, with no need to justify the figure in detail.
- A formal licence or rental agreement. The company pays you rent for the use of part of your home, supported by a written agreement and a calculation of actual costs. The rent is a deductible expense for the company but becomes income you must declare personally.
The right route depends on how much you work from home and how you extract value from the company. It interacts with decisions covered in extracting profit tax-efficiently, so it is worth viewing your home office claim as part of the bigger picture.
Capital gains considerations
A frequent worry is whether claiming for a home office puts your private residence relief at risk when you sell. The relief that normally exempts your main home from Capital Gains Tax can be restricted if part of the property is used exclusively for business.
In practice the risk is usually avoided where the rooms you use for work also have some private use, such as a spare bedroom that doubles as a study. Keeping a clear element of personal use protects the full relief while still allowing a sensible business claim. If you have a dedicated, exclusively business space, take advice before you sell.
Record keeping
Whichever method you choose, good records make the claim defensible and the year-end straightforward:
- Keep a log of hours worked from home if you use the flat rate.
- Retain utility, council tax, insurance and mortgage interest statements if you use actual costs.
- Note your apportionment calculation so it can be repeated each year.
- Store everything digitally, in line with digital record keeping and Making Tax Digital expectations.
Solid records also feed directly into your record keeping for expenses routine, reducing the scramble at filing time.