CIS Nil Returns: HMRC's Penalty Suspension Has Ended — What UK Contractors Must Do Before Sunday

From Sunday 6 April 2026, HMRC will enforce full late-filing penalties for CIS nil returns — for the first time in years. Many construction contractors stopped filing because nothing ever happened. That changes in 72 hours. Here's what you need to know and do before the deadline hits.

What Is a CIS Nil Return — and Why Did So Many Contractors Stop Filing?

Under the Construction Industry Scheme, registered contractors must file a monthly return to HMRC — even in months where no payments were made to subcontractors. This is the "nil return": a declaration that no payments were made.

HMRC suspended the escalating penalty regime for late CIS nil returns several years ago. In practice, this meant thousands of contractors simply stopped filing. No penalty arrived. The admin overhead seemed pointless. Why file a return saying nothing happened, when HMRC didn't seem to care?

That arrangement ends on Sunday.

From 6 April 2026, HMRC will reinstate the full escalating penalty ladder for missed CIS nil returns — effective from day one of the late return, with no grace period.

The current penalty regime:

£100 for returns up to 2 months late
£200 for returns 2 to 6 months late
£300 or 5% of the CIS amount (whichever is higher) for returns over 6 months late
Additional 5% of CIS amount or £3,000 (whichever is higher) for returns over 12 months late — with penalties for deliberate and concealed failures significantly higher

If you have contractors who haven't filed for 12+ months, the liability is not theoretical. It adds up fast.

Who Is Affected

Any UK contractor registered under the Construction Industry Scheme who is required to file monthly returns. This includes:

Main contractors and principal contractors engaging subcontractors
Specialist trades (electrical, plumbing, roofing, groundworks) paying subcontractors
Property developers using CIS-registered labour
Contractors who have filed nil returns in the past but stopped

If you weren't deregistered from CIS when you stopped paying subcontractors, you are still required to file monthly nil returns. HMRC does not automatically deregister contractors who stop using subcontractors.

Accountants and tax advisers: check your client list now. Any construction client registered with CIS who has lapsed their nil returns is walking into penalties on Sunday.

This Is One of Three CIS Changes Hitting on the Same Day

The nil return penalty reinstatement is the least-understood of three significant CIS changes all taking effect on 6 April 2026.

1. GPS Kittel Principle — Director Personal Liability

The Gross Payment Status Kittel principle now applies with formal enforcement powers. Construction company directors can be personally held liable for CIS payment failures linked to fraud in the supply chain. The penalty: a 30% surcharge on the unpaid CIS amount, a 5-year bar from GPS status, and — critically — personal liability for the director, not just the company.

The Kittel principle originated in EU VAT law but has been adopted into UK construction scheme enforcement. If your supply chain includes workers paid through arrangements HMRC considers fraudulent (including some umbrella structures), director-level consequences now apply under UK domestic law.

2. Umbrella PAYE Joint Liability

Also taking effect on Sunday: the umbrella PAYE joint liability provisions. End clients — the construction firms commissioning the work — can now be held jointly liable for PAYE and National Insurance contributions that umbrella payroll companies fail to hand over to HMRC.

Previously, if an umbrella company pocketed the employer's NIC rather than paying it, HMRC's dispute was with the umbrella. From 6 April, HMRC can send the bill directly to the end client.

This is not theoretical. HMRC has identified multiple umbrella companies operating non-compliant structures in the construction supply chain. End clients who have not verified their umbrella arrangements are exposed.

What Happened This Week: HSE Director Bans Construction Sector

While CIS changes are the regulatory focus for Sunday, the construction sector saw a sharp reminder this week of where personal liability enforcement is heading.

A site manager received a suspended prison sentence, a five-year director disqualification, and an electronic monitoring curfew after hiring an unlicensed contractor to remove asbestos from a demolition site. Two associated companies were fined a combined £88,300.

HSE inspectors are visiting construction sites unannounced right now — it is Global Asbestos Awareness Week (1–7 April 2026). Inspectors are checking asbestos management plans, staff training records, and disturbance procedures.

The combination of active HSE enforcement visits this week and three concurrent CIS changes on Sunday represents the most concentrated regulatory pressure the UK construction sector has faced in years.

What Contractors Need to Do Before Sunday

Step 1: Check Your CIS Registration Status

Log in to HMRC's CIS online service and confirm whether your business is still registered as a contractor. If you have not deregistered but have not been paying subcontractors, you owe nil returns for every month since your last filing.

Step 2: Identify Unfiled Periods

Pull your CIS filing history. List every month where a return was not submitted. This is your penalty exposure from Sunday onwards — and for any months already significantly overdue, penalties may apply retroactively under the reinstated regime.

Step 3: File Outstanding Nil Returns Now

File any outstanding nil returns before Sunday 6 April. This is the only way to eliminate the risk. HMRC's online service accepts nil returns for prior periods. If you have an accountant, ask them to clear the backlog today or tomorrow.

Step 4: Review Your Umbrella Arrangements

If you engage workers through umbrella payroll companies, request written confirmation that the arrangement is fully compliant with the PAYE Joint Liability regulations. Specifically:

The umbrella must be registered with HMRC
Employer NIC contributions must be paid to HMRC directly by the umbrella
You should hold a copy of their compliance confirmation

Step 5: Update Your GPS Risk Assessment

If your business holds Gross Payment Status, review whether any supply chain partners present a Kittel principle risk. This means checking that subcontractors and payroll arrangements in your supply chain are verified and compliant.

Why Most Contractors Don't Know This Is Coming

BDO and Saffery (two of the largest construction sector accountancy firms) have both confirmed in sector briefings that the CIS nil return penalty reinstatement has received almost no mainstream press coverage. SMB construction contractors — who rarely read trade press and rely on accountants to flag changes — are largely unaware.

HMRC has not issued a mass communication campaign. The change appears in technical guidance updates, not in letters to registered contractors.

This is the gap ComplianceAlert exists to close. We monitor HMRC, HSE, CIS, and all major regulators in real time — and we flag changes like this before the deadline, not the day after.

Frequently Asked Questions

Do I have to file a nil return if I didn't pay any subcontractors? Yes. If you are registered as a CIS contractor, you must file a monthly return even in months where no payments were made. This has always been the rule — the penalty suspension created a false impression that it was optional.

What if I deregistered from CIS? If you properly deregistered when you stopped using subcontractors, you are not required to file returns. But deregistration must be confirmed in writing by HMRC. Assuming you're deregistered because you stopped paying subcontractors is not sufficient.

Can I still file outstanding returns after April 6? Yes, but penalties will apply for any return that was due before 6 April and not filed by then. Filing after the deadline does not eliminate the penalty — it only stops it escalating further.

Is this the same as the CIS GPS director liability change? No. These are three separate changes: nil return penalties, GPS Kittel director liability, and umbrella PAYE joint liability. All three take effect on Sunday 6 April but each affects different aspects of CIS compliance.

What is the maximum penalty for late CIS nil returns? For returns over 12 months late, the penalty can be the greater of £3,000 or 5% of the CIS amount — plus higher penalties for deliberate non-compliance. If you have several years of unfiled nil returns across multiple companies, the cumulative exposure is significant.

The Bottom Line for Construction Contractors

Three things happen this Sunday that construction businesses need to act on now:

File every outstanding CIS nil return — the penalty suspension is over
Verify your umbrella payroll arrangements — joint liability starts Sunday
Review GPS supply chain risk — director personal liability is now formal

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CIS Nil Returns: HMRC's Penalty Suspension Has Ended — What UK Contractors Must Do Now