The CIS Deduction Rate HMRC Assigns By Default And Why It's Quietly Costing Your Subcontractors Thousands

Are You Losing Money to the Wrong CIS Rate?

If you work in the construction industry as a subcontractor, whether you're a sole trader, a limited company director, or a self-employed tradesperson, HMRC is almost certainly deducting tax from your pay before you even see it.

This is how the Construction Industry Scheme (CIS) works. Your contractor withholds a percentage of your labour payments and sends it directly to HMRC. The idea is sound: it prevents tax evasion in the construction sector.

The problem? Most subcontractors in the UK are sitting on the wrong rate.

HMRC's default deduction rate is 20% for registered subcontractors and 30% for unverified ones. For many construction workers, that means thousands of pounds being deducted each year, often far more than their actual tax liability. The money doesn't vanish, but if you don't know how to claim it back, it might as well have.

In this guide, YRF Accountants, CIS specialists based in Bolton, serving clients across Manchester, Bury, and the wider UK, break down exactly how CIS deduction rates work, who qualifies for a lower rate, and what you should do if you've been overpaying for years.

How CIS Deduction Rates Work in 2025/26

Under the Construction Industry Scheme, contractors are legally required to verify subcontractors with HMRC before making payment. The verification result determines which rate applies:

These aren't optional. The contractor must apply the rate HMRC assigns which is why getting verified and obtaining gross payment status (or at least net/standard status) matters so much.

Why Most Subcontractors End Up Overpaying

Problem 1: They Never Applied for Gross Payment Status

Gross payment status (GPS) means HMRC trusts you to manage your own tax. Under GPS, contractors pay you in full, no deduction at source. This is ideal for subcontractors with a strong compliance history.
To qualify in 2025/26, you must:

• Have a UK business bank account
• Have filed all Self-Assessment or Corporation Tax returns on time
• Meet the turnover threshold (£30,000 for sole traders, higher for companies)
• Have no history of serious HMRC non-compliance

Many subcontractors simply don't know GPS exists or assume they won't qualify. As a result, they carry on at 20% indefinitely.

Problem 2: They've Never Been Verified

If a contractor can't verify you through HMRC's systems because you haven't registered under CIS or your details don't match, they must deduct at 30%. This is the higher rate, and it applies automatically until the issue is resolved.
This catches many sole traders who work across multiple contractors. Each contractor must verify you independently, and a mismatch in your name, UTR, or trading details can trigger the 30% rate.

Problem 3: Their Tax Liability is Far Lower Than the Deductions

Even at the standard 20% rate, a subcontractor earning £50,000 gross in labour income would have £10,000 deducted before receiving a penny. Yet their actual Income Tax and National Insurance liability after allowances, expenses, and reliefs, might be considerably less.
The excess is a tax refund owed to the subcontractor. But HMRC won't issue it automatically. You need to file a Self-Assessment tax return and claim it.

What Happens to the Money HMRC Deducts?

CIS deductions are not lost. They are held against your Income Tax and National Insurance liability for the year. When you submit your Self-Assessment return, HMRC calculates:

• Your total income from all sources
• Your allowable business expenses
• Your personal allowance (£12,570 in 2025/26)
• Any other reliefs or deductions you're entitled to

If the CIS deductions already withheld exceed your final tax bill, HMRC issues a refund. In many cases, that refund can run into thousands of pounds.

Example refund scenarios (illustrative, based on 2025/26 rates):

These figures are illustrative only. Actual refunds depend on total income, allowable expenses, and individual tax circumstances. Always seek professional advice.

How to Apply for Gross Payment Status Under CIS

If you believe you qualify, you can apply for gross payment status by contacting HMRC directly or working with a specialist accountant. The process involves:

• Registering as a subcontractor under CIS (if not already done)
• Applying online via HMRC's CIS portal or by calling the CIS helpline
• Providing details of your turnover, compliance history, and business structure

HMRC will review your application and notify contractors of the new rate. This can take several weeks, so it's worth applying sooner rather than later every month on the wrong rate is money sitting with HMRC unnecessarily.
If your application is declined (due to compliance history, turnover, or other factors), don't give up. A qualified CIS accountant can often identify what's holding the application back and advise on remediation steps.

How to Reclaim CIS Overpayments: Self-Assessment

Whether you're a sole trader or operating through a limited company, recovering CIS overpayments requires filing a return with HMRC:

Sole Traders

File a Self-Assessment tax return (SA100) for each tax year. CIS deductions are reported on the supplementary page (SA103). If total deductions exceed your liability, HMRC will refund the difference — typically within a few weeks of the return being processed.

Limited Companies

CIS deductions suffered by a limited company can be offset against PAYE/NIC liabilities owed as an employer (if the company has a payroll). Any remaining excess can be reclaimed via the Corporation Tax return or by submitting a CIS repayment claim directly to HMRC.
Note: You can go back up to four years to claim CIS refunds you're owed. If you've been on the wrong rate for several years, the cumulative refund could be significant.

FAQs: CIS Deduction Rates

What is the standard CIS deduction rate in 2025/26?

The standard rate is 20% for registered and verified subcontractors. An unverified subcontractor is deducted at 30%. Subcontractors with gross payment status are deducted at 0%.

Can I get my CIS deductions back?

Yes. CIS deductions are offset against your tax liability when you file a Self-Assessment (sole trader) or Corporation Tax return (limited company). If deductions exceed your liability, HMRC refunds the difference.

How long does a CIS refund take from HMRC?

Most CIS refunds through Self-Assessment are processed within 2–8 weeks of the return being filed, provided your tax affairs are in order. More complex cases may take longer, particularly if HMRC selects the return for review.

How do I get gross payment status under CIS?

You can apply through HMRC's online CIS service or by calling the CIS helpline. You'll need to meet the turnover and compliance conditions. A specialist accountant can assess your eligibility and handle the application for you.

What if I've been on the 30% rate by mistake?

If you were deducted at 30% because a contractor couldn't verify you and you're actually a registered subcontractor, the overpaid tax is still recoverable through your Self-Assessment return. It's worth checking your CIS statements carefully.

Can YRF Accountants handle my CIS tax return?

Absolutely. YRF Accountants handles CIS tax returns for subcontractors and contractors across Bolton, Manchester, Bury, and nationwide. We can also advise on gross payment status applications and multi-year repayment claims.

The Bottom Line

The CIS deduction rate HMRC assigns by default is designed to be a tax collection mechanism — not an accurate reflection of what you owe. For thousands of subcontractors across the UK, the gap between what's deducted and what's owed is substantial.

If you haven't reviewed your CIS status, applied for gross payment status, or filed a Self-Assessment return to reclaim deductions, there's a good chance HMRC is holding money that belongs to you.