For UK CIS subcontractors

CIS Tax Refund Calculator — See What You're Owed

CIS is deducted at 20% or 30% from your very first pound, with no personal allowance applied at source. Almost every subcontractor ends up overpaying during the year — DayGraft estimates exactly how much, free, right inside the app.

Free to download · iPhone & iPad · Android phones and tablets
What it does

Built around real CIS work, not a generic timesheet

Why most subbies are owed money back

Your personal allowance (£12,570) and the actual tax bands aren't applied when CIS is deducted — the contractor just takes a flat 20% or 30% off your labour. That's almost always more than you actually owe once your real tax and National Insurance are worked out properly.

A real breakdown, not a guess

DayGraft's refund estimate shows the full working: turnover, expenses and mileage deducted, taxable profit, personal allowance, income tax, Class 4 National Insurance, and how much CIS has already come off — then the balance, in green if you're owed money back.

Built from records you're already keeping

There's nothing extra to fill in. The estimate is calculated automatically from the days, expenses and mileage you log in DayGraft as you go — for both Full Tracking and Simple Hours.

Covers Scotland and rUK tax bands separately

Scottish income tax bands are genuinely different from England, Wales and Northern Ireland. Set your region once in Settings and the estimate uses the correct bands and threshold for where you live.

Free — no card, no catch

The refund estimate is available on the free plan. You don't need to subscribe to see whether you're likely owed money back.

Questions

Before you download

How much CIS refund could I be owed?

It depends entirely on your income, expenses and mileage for the tax year — there's no single number that applies to everyone. A subcontractor earning around £45,000 with typical expenses is commonly owed somewhere between £1,500 and £3,000, but DayGraft calculates your own figure from your own logged records rather than a generic estimate.

Is a CIS refund calculator accurate, or just a rough guide?

DayGraft's estimate uses the real 2026/27 tax bands, personal allowance, and Class 4 National Insurance rates, and correctly excludes materials from the CIS-deductible amount. It's still an estimate for guidance — it assumes self-employment is your only income and that everything's been logged — so it's a strong starting point, not a substitute for your accountant or Self Assessment.

Do I need to pay a company to claim my CIS refund?

No. CIS refunds are claimed through your own Self Assessment tax return, which you or an accountant can file directly with HMRC. Refund companies typically take 25–35% of what you're owed for doing this on your behalf — DayGraft's estimate is designed to help you see the number yourself, for free, so you can decide whether you need that help at all.

Does this work if I'm on 30% CIS instead of 20%?

Yes — set your actual CIS rate in Settings and the estimate uses it. If you're on 30% because you're not CIS-registered, the numbers are usually the strongest argument for registering, since you're having considerably more deducted than a registered subcontractor doing identical work.

What information does DayGraft need to calculate this?

Nothing extra. It uses the days, expenses and mileage you're already logging to run the app day to day. There's no separate tax questionnaire to fill in.

Is the CIS refund calculator free to use?

Yes, it's part of DayGraft's free plan — no subscription or trial required to see your estimate.

Built by one developer.
Shaped by real subbies.

Download it, log tomorrow's day in ten seconds, and see if it earns its place in your pocket. Free to start, no account needed.

Free to download · iPhone & iPad · Android phones and tablets

Questions? Support · User guide