CIS Nil Returns

Key facts

A nil return must be filed for any tax month in which no payments were made to subcontractors.
The deadline is the same as a regular return: 19th of the following month.
Nil returns can be filed online or by phoning the CIS helpline on 0300 200 3210.
Failure to file a nil return attracts a £100 penalty from day one, just like a late return.
You can request HMRC to set your CIS scheme as inactive if you expect a prolonged period with no subcontractor payments.

What Is a CIS Nil Return?

A CIS nil return is a monthly CIS return (CIS300) submitted for a tax month in which the contractor made no payments to any subcontractors. It is essentially a declaration to HMRC that confirms: “I am still a registered CIS contractor, but I had no subcontractor payments this month.”^[1]

The nil return serves the same purpose as a regular return — it keeps HMRC’s records up to date and prevents them from treating a missing return as non-compliance.

When Is a Nil Return Required?

You must file a nil return if:^[1]

You are registered as a CIS contractor with HMRC
You did not make any payments to subcontractors during the tax month (6th to 5th)
Your CIS scheme is not set to inactive

Common situations where nil returns arise:

Seasonal work: Contractors who are busy in summer but quiet in winter
Between projects: A gap between finishing one job and starting the next
Newly registered: Registered for CIS but the first subcontractor hasn’t started work yet
Using employees only: Some months you might only use employees (reported via PAYE), not subcontractors

How to File a Nil Return

There are three ways to submit a nil return:^[1]

1. Online (HMRC Business Tax Account)

Sign in to your HMRC business tax account
Go to the Construction Industry Scheme section
Select “File a return”
Choose the relevant tax month
Declare that no payments were made (nil return)
Submit the return

2. Phone (CIS Helpline)

Call 0300 200 3210 (Monday to Friday, 8am to 6pm) and ask to file a nil CIS return. You will need your Accounts Office Reference and the tax month you are filing for.

3. Commercial Software

Most CIS-compatible accounting and payroll software can submit nil returns electronically to HMRC.

Tip: The quickest way to file a nil return is by phone. The call typically takes just a few minutes. If you know a month is going to be nil, call on or shortly after the 6th to get it out of the way early.

Nil Return Deadline

The deadline for a nil return is the same as for a regular return: the 19th of the month following the tax month.^[1]

For example, if you had no subcontractor payments in the tax month 6 October to 5 November, the nil return is due by 19 November.

Penalties for Missing Nil Returns

HMRC treats a missing nil return identically to any other late CIS return. The penalty regime is:^[2]

Lateness	Penalty
1 day late	£100 fixed penalty
2 months late	Additional £200
6 months late	Additional £300 (or 5% of deductions, but since deductions are nil, the minimum is £300)
12 months late	Additional £300

A single missed nil return costs at least £100. If several months are missed, the penalties accumulate rapidly. For example, missing 6 consecutive nil returns costs at least £600 in penalties.

This catches many contractors out. It is a common mistake to assume that no payments means no filing obligation. HMRC expects a return for every month your CIS scheme is active, and penalties are automatic.

Setting Your CIS Scheme to Inactive

If you expect to have no subcontractor payments for an extended period, you can ask HMRC to set your CIS scheme to inactive. This suspends the requirement to file monthly returns.^[3]

To request inactivity:

Call the CIS helpline on 0300 200 3210
Explain that you will not be making subcontractor payments for a period
HMRC will set your scheme to inactive and stop expecting monthly returns

When you are ready to start using subcontractors again, you must reactivate your scheme before making any payments. Call the helpline to reactivate.

Appealing Nil Return Penalties

If you receive a penalty for a late nil return and believe it is unfair, you can appeal to HMRC. You would need to demonstrate a reasonable excuse for the late filing, such as:

Serious illness or bereavement
HMRC system outage preventing online filing
Fire, flood, or other exceptional circumstances

“I forgot” or “I didn’t know I had to file” are not accepted as reasonable excuses.

Frequently Asked Questions

Do I really need to file a return if I made no payments?

Yes. If you are registered as a CIS contractor, HMRC expects a return for every tax month. If you made no payments to subcontractors, you must file a nil return confirming this. The alternative is to set your CIS scheme to inactive.

How do I file a CIS nil return?

You can file a nil return online through your HMRC business tax account (select “File a return” and declare nil payments), or by phoning the CIS helpline on 0300 200 3210. Some CIS software also supports nil return filing.

Can I file nil returns in advance?

No. You cannot file a nil return before the tax month has ended. You can only file it once the tax month (6th to 5th) has passed. However, you can file it as soon as the 6th of the following month.

What happens if I forget to file a nil return?

HMRC treats a missing nil return the same as any other late CIS return. A £100 penalty applies immediately, with further penalties at 2 months, 6 months, and 12 months. Multiple missed nil returns mean multiple penalties.

Sources

File your CIS monthly return — GOV.UK
CIS late filing penalties — GOV.UK
CIS: nil returns and inactivity (CISR46050) — HMRC