Introduction
If you work as a contractor in the UK construction industry, you are legally required to file monthly CIS (Construction Industry Scheme) returns to HMRC.
These returns show how much you’ve paid to subcontractors and how much CIS tax you’ve deducted from their payments.
In this guide, we’ll explain exactly what a CIS return is, the deadlines you must meet, and a step-by-step process to submit your return accurately.
What is a CIS Return?
The CIS return is a monthly report to HMRC detailing:
- Payments you’ve made to subcontractors
- Amounts of tax deducted (if applicable)
- Any subcontractors who were verified with HMRC during the period
If no payments were made in a given month, you still need to file a nil return.
When to File a CIS Return
- Frequency: Every month
- Deadline: By the 19th of the following month (e.g., for work done in June, file by 19 July)
- Penalties for late filing:
- £100 fine if even 1 day late
- £200 fine after 2 months
- Daily penalties if more than 6 months late
What You Need Before You File
Gather these details before starting:
- Subcontractor names and UTR numbers
- Verification numbers from HMRC (if applicable)
- Gross payments made to each subcontractor
- CIS deductions withheld
- Your HMRC Government Gateway login
Step-by-Step: How to File a CIS Return
Step 1: Log in to HMRC Online Services
Use your Government Gateway ID to access your CIS account.
Step 2: Select the Correct Filing Period
Choose the month you’re submitting for and confirm the dates.
Step 3: Enter Subcontractor Details
For each subcontractor, add their payment details and CIS deductions.
Step 4: Review the Summary
Double-check all amounts and ensure deductions are correct.
Step 5: Submit and Save Confirmation
Submit the return, and download/save the confirmation page for your records.
Common Mistakes to Avoid
- Forgetting to submit a nil return when no work was done
- Entering incorrect subcontractor verification numbers
- Missing the 19th of the month deadline
Frequently Asked Questions
Q: What happens if I miss the CIS return deadline?
A: HMRC will apply immediate penalties starting at £100, increasing the longer it’s late.
Q: Can I amend a CIS return?
A: Yes, you can correct mistakes by submitting an amended return through HMRC.
Conclusion & Call to Action
Filing your CIS return on time keeps your business compliant and avoids unnecessary HMRC fines.
If you want a stress-free experience, our team at Swift Ledger can manage your CIS returns each month, ensuring accuracy and timely submission.