CIS Return Deadline: When to File and Pay Each Month

The CIS return deadline is the 19th of each month. Your return covers the tax month that ended on the 5th, and HMRC must have it by the 19th. The money you deducted from subcontractors is due by the 22nd, or the 19th if you pay by post.

This guide lists every remaining date for the 2026/27 tax year, flags the ones that land on a weekend, and sets out the month-end routine our team follows. It is written for contractors in the Construction Industry Scheme, from sole-trader builders to small limited companies. If you want someone else to handle the paperwork, see our accounting services for UK contractors or speak to House Of Accounts' ACCA-qualified team.

How does the CIS tax month work?

A CIS tax month runs from the 6th of one month to the 5th of the next.

GOV.UK gives this example: a return for the tax month 6 May to 5 June must reach HMRC by 19 June. So a payment you make to a subcontractor on 3 June belongs to the May–June tax month, while a payment on 7 June falls into the next one.

Date each payment to a subcontractor by the day you actually paid it, then sort it into the right 6th-to-5th window. The official rules are on GOV.UK: file your monthly CIS returns.

CIS return and payment dates for the rest of 2026/27

The CIS monthly return deadline and the payment deadline for each remaining tax month are below. We have checked the weekday of every date.

What if a date falls on a weekend?

GOV.UK's CIS guidance does not say that a deadline moves when it falls on a weekend or bank holiday. For November and December 2026, plan to file and pay on the last working day before the weekend date: Friday 20 November for the payment, and Friday 18 December for the return.

Paying HMRC: the 19th or the 22nd?

It depends on how you pay. GOV.UK says to pay HMRC every month by the 22nd, or by the 19th if you are paying by post. A posted cheque must reach HMRC by the 19th.

You pay CIS deductions using the same methods as PAYE and National Insurance. If you already have employees, HMRC changes your existing PAYE scheme into a PAYE/CIS scheme. You then make one payment that covers PAYE tax, National Insurance and CIS deductions together.

If you pay HMRC quarterly rather than monthly, the payment is due by the 22nd after the end of the quarter, for example 22 July for the 6 April to 5 July quarter. Your CIS return is still due by the 19th of every month. HMRC may charge interest and penalties if you pay late.

Months with no payments: nil return or inactive?

GOV.UK says to send your return by the 19th of every month. If you paid no subcontractors in a tax month, you can file a nil return showing zero payments. If you have stopped using subcontractors for a while, you can tell HMRC with an inactivity request.

Subcontractor statements: the 14-day rule

If you make deductions, you must give each subcontractor a payment and deduction statement within 14 days of the end of the tax month. In practice that is also the 19th. For the 6 May to 5 June tax month, the statement is due by 19 June.

It sits alongside the return rather than inside it, so build it into the same month-end step.

Our month-end CIS routine

This is the checklist our team works through for contractors who use our CIS returns service.

1. Collect the month's records after the 5th. Gather every invoice and payment to subcontractors dated 6th to 5th.
2. Verify any new subcontractors. Check with HMRC that each new subcontractor is registered.
3. Apply the right deduction rate. Deduct 20% for registered subcontractors, 30% for unregistered ones and 0% for those with gross payment status. Take off amounts such as VAT, and materials the subcontractor paid for directly, before applying the rate.
4. Issue payment and deduction statements. Send each subcontractor their statement within 14 days of the tax month end.
5. File the return and pay. Submit the return by the 19th, then pay by the 22nd (or the 19th by post). Note any weekend dates from the table above.

One honest limit: we cannot file on time without your payment records, so we agree a date each month for you to send them. As the contractor, the duty to file sits with you, so keep an eye on the dates even when we file for you. If returns are already overdue, or a subcontractor disputes the deduction rate you used, contact us before the next deadline rather than after.

What if you've already missed a deadline?

File the overdue return now. HMRC charges a £100 penalty for a return that is one day late, and the amount rises the longer it stays outstanding. Paying late can also bring interest and penalties.