Home Office Tax Claim for Directors 2026-27: Flat Rate vs Apportioned Method

Most directors working from home are entitled to claim home office costs through their limited company — but the majority either don't claim at all, or claim only the HMRC flat rate without checking whether the actual cost method would save them more.

The flat rate (£6 per week, or £312 per year) takes two minutes to set up and gives the company a corporation tax saving of around £59–£78. The apportioned method often produces a deduction of £1,000–£3,000 — worth three to ten times as much. The right choice depends on your setup, but the comparison is worth running before you decide.

Why home office matters for directors (and not employees)

Since the end of the pandemic home working provisions, employees can no longer claim home office expenses unless they're specifically reimbursed by their employer. Directors are different: because you control your company, your company can reimburse you for genuine business use of your home — reducing company profit and saving corporation tax.

This isn't a grey area or an aggressive claim. It's explicitly HMRC-approved, with two official methods: the flat rate and the apportioned actual costs method. Most directors use neither, leaving real money on the table every year.

Method 1: The HMRC flat rate (the easy win)

HMRC allows a £6 per week home working payment, no receipts required, as long as you work from home for at least 25 hours per month. That's £312 per year. Your company pays this to you as an expense reimbursement. The saving:

• Corporation tax at 19% (small profits rate): £59.28 per year saved
• Corporation tax at 25% (main rate): £78 per year saved

Not life-changing money, but it's completely frictionless. No receipts, no calculation, no risk. Every director who works from home should claim this as an absolute minimum.

Method 2: Apportioned actual costs (the real saving)

The apportioned method calculates what proportion of your actual home running costs are attributable to business use. The formula: (number of rooms used for business ÷ total rooms) × total annual home running costs.

Here's a worked example for a director in a 4-bedroom house with one study used for business:

Room ratio: 1 room used for work out of 5 total rooms (3 bedrooms + 1 study + living room, roughly) = 20%.

Annual deductible amount: £18,900 × 20% = £3,780.

Corporation tax saving at 25%: £945 versus £78 on the flat rate.

For minimal extra effort — gathering utility bills and doing a simple calculation once per year — you're saving nearly £1,000 in tax instead of £78. The comparison isn't even close.

Golden nugget: mortgage capital repayments don't count, but interest does

Only the interest portion of your mortgage qualifies — not the capital repayment portion. If your monthly payment is £1,500 but £400 is capital repayment, you use £1,100 as the monthly cost. Check your annual mortgage statement to get the interest figure for the year. Overstating this by including capital repayment is one of the more common errors HMRC investigates.

The CGT trap — and the simple way to avoid it

Here's the risk that puts some directors off the apportioned method: if a room is used exclusively for business — nothing personal, ever — it could lose Private Residence Relief when you sell your home. PRR exempts the main residence from Capital Gains Tax. Lose it on 20% of the property, and 20% of any capital gain could be taxable.

The fix is simple: make sure your office is also used personally. Let your children do homework in there. Keep a bookshelf you read from. Use it as a reading room at weekends. HMRC's guidance states that shared use rooms — used for both business and personal purposes — do not trigger the PRR restriction. You keep full CGT exemption and the home office deduction.

This is not aggressive tax planning. It's common sense. Keep the room as a shared space and you have no CGT risk at all.

Renting a room to your company

There's a third option some directors use: their company pays them formal rent for the use of a room in their home. This creates rental income for the director (taxed as property income, not salary — so no NI) and a company expense deduction. The arrangement requires a genuine licence agreement and a commercially reasonable rent. If done correctly, it can produce a larger deduction than either of the HMRC-approved methods.

The downside: rental income above £1,000 (property income allowance) must be reported on Self Assessment, and the arrangement adds complexity. It's most worthwhile for directors in higher-rate tax bands who can afford specialist advice to set it up correctly.

Golden nugget: use the Home Office calculator to compare

Input your actual home costs, number of rooms, and business rooms — the calculator shows both the flat rate saving and the apportioned saving side by side. Most directors see a 5–10x difference in favour of the apportioned method. The calculation takes 10 minutes. The tax saving lasts all year.