CIS Monthly Returns & Payment Compliance: Deadlines Contractors Can’t Miss

Why CIS Returns Are High-Risk for Contractors

Every CIS contractor must file monthly returns to HMRC — even if no subcontractors were paid that month. This “nil return” rule catches many contractors off guard.

Missing just one deadline can trigger automatic HMRC penalties, while incorrect returns can lead to costly interest charges. For contractors already juggling projects, payroll, and cash flow, these extra compliance duties are easy to overlook.

This article explains CIS monthly return obligations, deadlines, penalties, and why expert management is the safest way to stay compliant.

CIS Monthly Returns: What You Must File

Contractors must submit a CIS return every month, which includes:

• Subcontractor details (name, UTR, verification number).

• Payments made in the period.

• Deductions applied at 20% or 30%.

• Confirmation that all subcontractors are verified.

👉 Even if you made no payments, you must file a nil return. Failure to do so triggers the same penalties as late or incorrect returns.

🔗 HMRC: CIS Returns – What Contractors Must Do

Key Deadlines Contractors Must Meet

• Monthly CIS return deadline → 19th of the following month.

• PAYE/NIC payment deadline → 22nd of the following month (if paying electronically).

• Nil returns → required if no subcontractors were paid.

For example: deductions made in April must be reported by 19 May, with payment cleared to HMRC by 22 May.

Penalties for Late or Incorrect Returns

HMRC applies automatic penalties if monthly CIS returns are late:

• £100 → 1 day late.

• £200 → 2 months late.

• £300 or 5% of deductions (whichever is higher) → 6 months late.

• Further £300 or 5% → 12 months late.

Additional risks include:

• Interest charges on late CIS payments.

• Fines for incorrect or false statements.

• Increased HMRC scrutiny for repeat failures.

🔗 HMRC: CIS Penalties

Common Pitfalls in CIS Compliance

Contractors often fall into traps such as:

• Forgetting to file nil returns.

• Missing the 19th deadline due to project commitments.

• Submitting incorrect subcontractor details.

• Paying HMRC late despite filing on time.

These errors can stack penalties quickly — eating into profit margins and damaging subcontractor relationships.

How Wexley Protects Contractors from CIS Penalties

At Wexley & Associates, we ensure our contractor clients never miss a CIS deadline. We:

• File all monthly returns on time, including nil returns.

• Verify deductions are accurate before submission.

• Manage PAYE/NIC and CIS payment deadlines.

• Represent clients in case of HMRC queries or disputes.

With us, contractors avoid the constant risk of penalties and stay focused on running projects profitably.

Stay Ahead of CIS Deadlines with Wexley

CIS monthly returns are a constant compliance burden, but missing them even once can be expensive. The safest approach is to have a professional firm manage the process for you.

👉 Contact Wexley & Associates today for expert CIS management that keeps you compliant, penalty-free, and stress-free.

References

• HMRC: CIS 340 – Construction Industry Scheme: Guide for Contractors and Subcontractors

• HMRC: CIS Returns – What Contractors Must Do

• HMRC: CIS Penalties

• Related Wex Insider article: CIS Deduction Rules & Rates: What Every Contractor Must Know