Who is a CIS subcontractor?

Anyone in UK construction working under another company on a contract basis (not employed/PAYE). Typical examples: bricklayer, painter, plumber, electrician working day-rate.

How long for the refund?

6–12 weeks after Self Assessment submission. Paid directly to a UK bank account. Larger refunds (£10,000+) trigger a compliance check and may take longer.

What is a CIS statement?

Monthly document from the contractor showing gross income plus 20% (or 30%) deduction. Keep all statements — needed for Self Assessment. Contractor must provide it within 14 days of month-end.

What is CIS and who must register?

CIS (Construction Industry Scheme) is an advance tax deduction system for construction subcontractors. All self-employed subcontractors in construction must register. Without registration the contractor deducts 30% instead of 20%.

How much does the contractor deduct under CIS?

20% — standard deduction if you are verified with HMRC. 30% — if the contractor could not verify your UTR. 0% — Gross Payment Status for experienced subcontractors with a history.

How do I get a refund of overpaid CIS tax?

Only through Self Assessment. You need to file SA100 + SA103S and enter the exact amount of CIS deductions suffered from your monthly statements. HMRC recalculates taking into account Personal Allowance and expenses — the difference is refunded to your account.

How much can I actually get back through CIS Self Assessment?

With an income of £40,000 and expenses of £5,000 a typical refund is £3,500–6,000. CIS is deducted from gross income without considering Personal Allowance (£12,570) and expenses — so the real tax is 3–4 times lower than the amount deducted.

What can I include as expenses for CIS Self Assessment?

Tools and equipment, PPE (protective clothing, boots), public liability insurance, site-to-site transport (45p/mile up to 10,000 miles), phone (business portion), accountancy fees. Not allowed: ordinary commute, personal food, fines.

What is a CIS Monthly Statement and why should I keep it?

The contractor must issue a CIS statement within 14 days after the end of each tax month. It shows: gross amount, CIS deduction, net payment. This is the main proof of tax deducted for SA. Keep it for at least 5 years.

What is the deadline for filing Self Assessment for CIS?

The online deadline is 31 January (for the previous tax year). For example, SA for 2025/26 must be filed by 31 January 2027. Missing the deadline — automatic £100 penalty.

Updated 2026-05-21

CIS (Construction Industry Scheme) is a UK tax deduction system for construction subcontractors. The contractor withholds 20% (registered) or 30% (unregistered) of gross income. Refund only via Self Assessment SA103S; deadline 31 January online.

In short

CIS is a tax deduction system for construction subcontractors in the UK: the contractor deducts 20% (or 30% if you are not verified) from each payment. The real tax, taking into account Personal Allowance (£12,570) and expenses, is 3–4 times lower: with an income of £40,000 a typical refund is £3,500–6,000. You can get the overpaid amount back only through Self Assessment — free on gov.uk, deadline 31 January.

CIS · biggest segment · updated May 2026

CIS subcontractor — refund £2,000–£6,000 per year.

Q: How to register for CIS?

Online at gov.uk/register-cis-subcontractor. You need a UTR (Self Assessment UTR — apply first if you have no UTR). Registration drops withholding from 30% to 20%.

The contractor deducts 20% from each payment. But your real tax is 3–4 times lower. Self Assessment returns the difference. It is legal, free, and you can do it yourself.

Why the refund is big →How to get a refund

How it works

How CIS works — three rates.

Construction Industry Scheme (CIS) is an advance tax deduction system. The contractor (main contractor) deducts money from your payment and sends it to HMRC.

20%

Standard deduction

You are registered as a CIS subcontractor, the contractor verified you with HMRC using your UTR and name. This is normal.

30%

Higher deduction

The contractor could not verify your UTR with HMRC — for example, the name does not match, the UTR is wrong, or you are not registered. The losses are significant.

Gross Payment Status

HMRC allows you to receive 100% of the payment without deductions. Requirements: 12+ months in business, a history of tax payments, turnover from £30,000.

Contractor obligations under CIS

According to CIS340 (HMRC guide) the contractor must: verify each subcontractor with HMRC before the first payment; issue a Monthly Payment and Deduction Statement within 14 days after the end of each tax month; submit a Monthly CIS Return to HMRC. This is not goodwill — it is the law.

GPS — April 2026: new rule

From April 2026 HMRC has the right to revoke Gross Payment Status immediately if fraud is suspected in the supply chain. After revocation, GPS can be restored no earlier than 5 years later. If you have GPS — full compliance is mandatory.

Why so much

The maths of the refund.

CIS is deducted from gross income. Personal Allowance and expenses are not taken into account when the deduction is made. After SA the difference is returned.

Example: £40,000 gross / year

Gross CIS income£40,000

CIS deducted (20%)−£8,000

Personal Allowance−£12,570

Allowable expenses (tools, PPE, insurance, transport)−£5,000

Taxable income£22,430

Real tax (20%)£4,486

Refund (£8,000 − £4,486)≈ £3,514

With higher expenses (£8,000+) the refund exceeds £5,000. Builders with expenses of £10K+ regularly get £6,000+.

Why expenses are so important

Every £1 of documented expenses reduces your taxable income. At the basic rate of 20% — that is £0.20 refund per £1. With £5,000 of expenses — +£1,000 to your refund. Keep all receipts.

Mileage between sites

Travel from site to site — 45p/mile (first 10,000 miles/year). Keep a mileage log: date, route, distance. This is one of the biggest sources of deductions for CIS.

Expenses

What you can deduct — and what you cannot.

HMRC test: «wholly and exclusively» for business. Any expense with a personal element must be split proportionally.

Allowable expenses

Tools and equipmentDrills, angle grinders, measuring instruments. Purchase or hire. Small cost — deduct immediately; large items — through capital allowances.

PPESafety boots, helmet, gloves, vest, goggles. Fully deductible — this is a work necessity, not clothing.

Public liability insuranceMandatory on most sites. 100% deductible.

Transport site-to-siteTravel between sites: 45p/mile up to 10,000 miles, 25p/mile above. NOT the journey from home to the first site.

Phone and internet (business portion)Business use portion. If the phone is 50% for work — deduct 50% of the bill.

Accountancy feesAccountant's fee for preparing SA — fully deductible.

Home office (proportionally)If you work from home (calls, invoices, documents) — proportional part of rent/mortgage interest, utilities.

Not allowed

Ordinary commuteTravel from home to a permanent site — personal expense, not business.

Personal clothingOrdinary clothes, even if you wear them at work. Only specialised protective clothing (PPE).

Food and drinkLunch on the construction site — personal expense. Exception: overnight stays away from home (subsistence on a business trip).

FinesParking fine, speeding ticket — not deductible even if on a work route.

Documents

Monthly CIS statements — keep every one.

The CIS statement is your main proof of tax deducted. Without it HMRC cannot match your data with the contractor's data.

What a CIS statement contains

01Subcontractor name and UTR

02Period (tax month)

03Gross amount paid (before deduction)

04CIS deduction (tax deducted)

05Net payment (what you received)

06Materials (if included — they are not subject to CIS)

What to do if the contractor does not issue a statement

This is a breach of the law. Your steps:

Send a written request. By email or letter — keep a copy. Set a 14-day deadline.
If no response — complain to HMRC. 0300 200 3210 (CIS helpline). HMRC can fine the contractor.
Do not submit SA without documents. It is better to delay than to enter the wrong amount of CIS deductions — this will delay or block the refund.

5-year record keeping

HMRC requires you to keep all CIS statements for at least 5 years after filing SA. Take photos and store them in the cloud — paper copies get lost.

Registration

How to register for CIS.

Without registration with HMRC the contractor applies 30% instead of 20%. Losses over a year are thousands of pounds.

Register as self-employed

gov.uk/register-for-self-employment (CWF1). Get a UTR (≈15 working days by post). Without a UTR the contractor cannot verify you.

Register as a CIS subcontractor

Call the HMRC CIS helpline (0300 200 3210) or register online. You need a UTR, NI number, full name (exactly as in HMRC records).

Give your UTR to each contractor

The contractor verifies you with HMRC using your UTR + name before the first payment. Make sure the name matches — one wrong letter → 30%.

Submit your first SA by 31 January

SA for your first year working as CIS. If you started in 2025/26 — submit by 31 January 2027.

The name must match exactly

HMRC verifies by name AND UTR. If the contractor enters «Alex» instead of «Alexander» or the wrong transliteration — verification fails and 30% applies. Use the name exactly as in HMRC records.

Refund

How to get a refund through SA.

A CIS refund only comes through Self Assessment — not through P800 and not through Personal Tax Account. There is no other way.

Соберите документы

P60, P45, CIS statements, банковские проценты, дивиденды, доход от аренды.

Получите UTR

Если первая декларация — регистрация на gov.uk. ~15 рабочих дней по почте.

Government Gateway

Заведите личный кабинет HMRC. Сохраните пароль офлайн — восстановление долгое.

Заполните SA100

Основная форма. Доходы, расходы, allowances. Online — проще, чем бумага.

Дополнительные секции

SA103 для self-employed, SA105 для аренды, SA106 для иностранного дохода.

Проверьте расчёт

HMRC покажет итог: должны вы или вам. Сверьте с собственной таблицей.

Подайте и оплатите

Дедлайн online: 31 января. Бумажный: 31 октября. Штраф £100 за просрочку.

CIS specifics in SA103S

Turnover field

Enter GROSS income — the amount before CIS deductions, as shown in the statements. Not the net amount you received into your account.

Expenses field

All allowable business expenses with supporting documents. HMRC may ask for proof — you must have the receipts.

CIS deductions suffered

The EXACT amount from all CIS statements for the year. HMRC checks it against the contractor's data — a mismatch delays the refund.

Errors

What delays the refund.

Most delays are technical. They can be prevented.

Name/NI mismatch

The name in SA does not match the name in HMRC records (or the contractor's records). HMRC pauses processing for manual review.

CIS deductions ≠ contractor data

You entered £5,000 CIS deductions, but the contractor reported £4,800. HMRC will ask for clarification. Only use numbers from official statements.

Missing bank details

If you do not provide bank details for BACS — HMRC will send a cheque by post. This is much slower.

Gross instead of net in Turnover

Some people enter the net amount (what they received) instead of gross. Then CIS deductions become a «double deduction» — SA gives an incorrect result.

Timeline

How long to wait for a refund.

HMRC does not publish fixed SLAs for CIS refunds. Actual times depend on HMRC's workload and the complexity of your claim.

Weeks, not days

Simple online SA with BACS — usually 4–8 weeks. Complex cases, paper SA, or if HMRC asks for additional documents — it can take several months. Do not call before 8 weeks after submission.

Check the status in your HMRC online account → Self Assessment → «View your SA calculation».

Important · agents

CIS workers — RIFT's main target.

RIFT charges £354 fixed fee for CIS — it is not «free». On a refund of £3,000 that is 11.8%. Through SA yourself — £0.

£3,000 refund · кто сколько оставит вам в кармане

Один и тот же возврат. Четыре цены.

HMRC возвращает одну и ту же сумму вне зависимости от посредника. Разница — только сколько посредник возьмёт себе.

DIY (сам через gov.uk)

Бесплатно. 90 минут вашего времени.

£3,000

никакой комиссии

У вас на счёте £3,000

Bookkeeper / accountant

Фикс-прайс. Видит всю картину.

£2,700

− £300 комиссия

У вас на счёте £2,700

Tax Returned

28% + VAT. «Бесплатная подача» — за этой фразой 33% комиссия.

£1,992

− £1,008 комиссия

У вас на счёте £1,992

RIFT

36% incl VAT. Реклама на стройках и в WhatsApp.

£1,920

− £1,080 комиссия

У вас на счёте £1,920

Full breakdown of RIFT and Tax Returned →

What next.

Sources