Working from Home Tax Deductions for the Self-Employed: 2026/27 Guide

If you work from home as a self-employed person, you can claim a proportion of your household running costs as a business expense — reducing your taxable profit and, consequently, the tax and National Insurance you pay. The claim is genuinely valuable, especially for people who work from home full-time, but the rules are more nuanced than most guides suggest.

There are two permitted methods: the simplified flat-rate system and the actual cost apportionment method. The right choice depends on your specific home and working pattern.

Why the deduction matters

As a sole trader, every pound of allowable business expense reduces your profit. A reduction in profit directly reduces:

Your income tax liability (at your marginal rate — 20% for basic rate taxpayers, 40% for higher rate)
Your Class 4 National Insurance liability (at 6% in 2026/27 for the main rate band)

So a £2,000 annual claim for use of home as office saves a basic rate taxpayer roughly £520 in combined tax and NI (£2,000 × 26%). For a higher rate taxpayer, the saving is closer to £840. These are meaningful sums over the course of a year.

Method 1: The simplified flat-rate method

HMRC's simplified expenses scheme offers a flat weekly rate based on the number of hours per month you use your home for work. The rates for 2026/27 are:

| Hours used per month | Monthly allowance | |---|---| | 25 to 50 hours | £10 | | 51 to 100 hours | £18 | | 101 hours or more | £26 |

These are monthly figures. Annual maximum at the highest tier: £312.

The simplified method is exactly what it sounds like — simple. You do not need to calculate the actual proportion of your household costs used for business. You just record your working hours, apply the applicable rate, and claim the flat amount. HMRC accepts this without further documentation.

Who this suits: Anyone who wants a straightforward deduction without calculating exact household costs. It's particularly useful for people who only work from home part-time or whose home costs are modest (small flat, low bills).

Who this doesn't suit: Anyone who works exclusively from home and has significant housing costs (rent, mortgage interest for limited companies, council tax, utilities). For these people, the actual cost method is almost always higher.

Use the Simplified Expenses Home Calculator to find your annual entitlement based on your monthly hours.

Method 2: Actual cost apportionment

The actual cost method requires you to calculate what proportion of your total household costs relates to business use, based on the number of rooms used for work and the time spent using them.

Step 1 — Calculate the business proportion of your home:

Divide the number of rooms used exclusively or regularly for business by the total number of rooms in your home. For example, if you have a 5-room home and use one room as a dedicated office, the business proportion is 1/5 = 20%.

Some people prefer to use floor space rather than room count — HMRC accepts either, provided the basis is consistent and reasonable.

Step 2 — Apply a time factor:

If the room is only used for business during working hours (not as a bedroom or living space at other times), a time factor applies. If you work 8 hours a day, 5 days a week — roughly 40 hours out of the 168 hours in a week — the time-use factor is approximately 24%.

Step 3 — Apply to qualifying costs:

The business proportion × time factor is applied to your total allowable household costs. Qualifying costs include:

Rent (if renting)
Mortgage interest — note: for sole traders, only mortgage interest is allowable, not the capital repayment portion
Council tax
Heating and electricity
Water (where linked to business use)
Home insurance (proportion related to business use)
Broadband (where primarily used for business)

Example:

Monthly household costs (rent, utilities, council tax, broadband): £1,800
Business proportion: 1/5 = 20%
Time factor: 40 hours work / 168 hours in week = 24%
Monthly business claim: £1,800 × 20% × 24% = £86.40
Annual claim: £1,036.80

This significantly exceeds the simplified method maximum of £312. For anyone working full-time from home in a house or larger flat, the actual cost method will almost always yield a higher deduction.

Use the Use of Home Calculator to calculate the apportionment method for your specific costs and working pattern.

The dedicated room issue

One important nuance: HMRC distinguishes between a room used exclusively for business and a room used for business alongside personal activities.

If you have a genuine dedicated office — a room that is only ever used for work, never as a guest room, never for personal use — you can claim the full proportion of costs for that room without a time-use discount. The room is 100% business use.

If you work at the kitchen table or in the living room, you must apply a time-use factor because those rooms serve mixed purposes. For most sole traders working at home, a genuine dedicated office is the most tax-efficient arrangement.

However, there is one complication. For sole traders (not limited companies), having a room dedicated exclusively to business may affect Private Residence Relief if you sell the property. HMRC may argue that a proportion of the gain is subject to capital gains tax. In practice, for modest claims and typical residential properties, this risk is minimal — but it's worth noting if you own your home and make very large use-of-home claims.

This issue does not apply to the simplified flat-rate method, which is specifically designed to avoid the CGT complication.

Employees who work from home

The rules above are for self-employed people. Employed individuals working from home have different rules — they can claim through the HMRC working from home allowance (£6/week, £312/year) if their employer doesn't reimburse them, or claim actual additional costs through the employment expenses process if higher and they have a tax office requirement. The self-employed deductions described above do not apply to employment income.

What you cannot claim

Certain home costs are not allowable for the use-of-home deduction:

Mortgage capital repayments — only interest is allowable (and for sole traders, even then the deduction is proportional)
Costs of a room used purely for personal purposes — clearly cannot be claimed as business
Improvements to the property — these are capital expenditure, not running costs
Rent for your desk space if a separate arrangement — may be treated as self-supply and cause complications

Keeping records

Whether you use the simplified method or actual cost method, keep records to support your claim:

For simplified: a log of working hours each month (or a reliable estimate — HMRC accepts reasonable calculations)
For actual cost: utility bills, council tax statements, rent or mortgage statements, and a written calculation showing the proportion used

HMRC can request these during an enquiry. Keeping them for six years after the relevant tax year is the standard retention requirement.

The Expenses Checker can help you identify all the expenses you're entitled to claim as a self-employed person, of which use of home is just one.