Doing quotes and invoices at the kitchen table: the £10, £18 or £26 a month flat rate for working from home, and the hours that decide it

The van is on the drive by 5pm. The quotes, the invoices and the VAT sheet get done at the kitchen table after tea. Plenty of tradespeople never claim a penny for it, because working out the share of the electricity bill sounds like an accountant's job. GOV.UK gives a shortcut with three fixed figures.

The three rates

GOV.UK's simplified expenses page for working from home sets a flat rate per month by the hours you work from home:

Three conditions from the same page:

• You can only use simplified expenses if you work 25 hours or more a month from home.
• The flat rate covers home running costs, so you do not need to split bills between personal and business use.
• It does not cover telephone or internet. For those you can claim the business proportion of the actual bills.

You can also use actual costs for home expenses instead of the flat rate. GOV.UK points to a simplified expenses checker to compare the two.

What the hours mean in a week

A month is 52 ÷ 12 weeks, about 4.33. Turning the thresholds into a week:

• 25 hours a month is 25 × 12 ÷ 52 = 5.77 hours a week, nearly 6 hours.
• 50 hours is 11.54 hours a week.
• 100 hours is 23.08 hours a week.

So three people who work from home:

1. Six hours a week (two evenings of quotes and invoices): about 26 hours a month, £10 a month, £120 a year.
2. Twelve hours a week (a long Sunday plus evenings): about 52 hours, £18 a month, £216 a year.
3. Twenty-four hours a week (a firm owner running the diary, wages and CIS from home): about 104 hours, £26 a month, £312 a year.

What it is worth

The claim is an expense, so it saves tax at your own rate. At 20% income tax that is £24, £43.20 and £62.40 a year for the three people above. It is modest money. The extra hour that tips a month from 50 hours to 51 adds £8 a month, £96 a year, of expenses.

A log kept as you go makes it easy to stand behind. Write down the hours at home each week (quotes, invoices, ordering, CIS, bookkeeping), and total them by month. The page does not say what proof HMRC will ask for, so ask your accountant what to keep.

What it does not cover

• Phone and internet. Claim the business share separately from the actual bills.
• Costs of the work itself. Mileage and tools are other claims; see the 55p mileage rate or actual costs.
• Another £1,000 route. A trading allowance on side income is a different rule, covered in the trading allowance guide.

If hours at home are a lot of your week, the day rate calculator can show how unpaid paperwork evenings affect what you earn per hour. Quarterly reporting will make a monthly record more useful, as the Making Tax Digital guide for tradespeople explains.

Overlyft builds AI staff who join a trades firm's office and keep a weekly log of paperwork hours, total each month's hours against the three bands and send the owner a short note to confirm before it reaches the accountant, so the claim has its evidence.

This is general information, not tax advice. Check GOV.UK and your own figures with your accountant.