What is the CIS monthly return?
Answered 17 March 2026
Based on the retrieved sources, here is a comprehensive answer:
The CIS Monthly Return
HMRC Guidance / Practice
What it is
The CIS monthly return (form CIS300) is a return that every contractor who makes payments to subcontractors in respect of construction operations must send to HMRC every month. It replaced the old annual return (CIS36) and the voucher paper trail from 6 April 2007 onwards.
Who must file it
Every contractor who makes payments to subcontractors in respect of construction operations is obliged to submit a monthly return.
What it contains
The return must include details of all payments made to subcontractors in respect of construction operations, including:
- Payments made gross
- Payments made under deduction at the standard rate
- Payments made under deduction at the higher rate
It also includes details of any deductions made from those payments.
CIS deductions are made on account of the subcontractor's income tax (and in certain circumstances Class 4 NIC) liability.
The return period
The return period covers an income tax month — that is, from the 6th of one month to the 5th of the next.
Due date
Returns are due by the 19th of the month following the end of each tax month.
Nil returns / inactivity
- Prior to April 2015, contractors had to make nil returns if no payments were made to subcontractors in the month.
- From 6 April 2015, contractors with no payments under a construction contract are no longer obliged to submit a nil return, but must still notify HMRC (e.g. by calling the CIS Helpline) to avoid a late-filing penalty and a specified charge.
- Contractors can also request a period of inactivity (up to 6 months) on the return if they do not expect to pay any subcontractors for the foreseeable future.
Automatic generation cycle
HMRC's CIS system automatically generates and issues returns on the following cycle: | Date | Event | |------|-------| | 5th of month | End of reporting period | | 6th of month | Start of new reporting period | | 19th of month | Due date for the previous month's return | | 24th of month | CIS system generates returns for the next period | | 29th of month | All auto-generated returns issued to contractors |
Penalties for non-filing
If a return is not received by the due date, HMRC will raise late-filing penalties. Where no return is received, HMRC's ETMP system will also calculate and raise a CIS specified charge based on the average amount due on previous CIS charges received, under Regulation 11 of the Income Tax (Construction Industry Scheme) Regulations 2005.
Citation sources
| CISR62600 | Action guide contents | |—————————————————————————————————–|———————–| The contractor returns process is vital to the success of the Construction Industry Scheme. Every contractor who makes payments to subcontractors in respect of construction operations must send a return with details of these to HMRC. These returns are due on a monthly basis. The return period covers an income tax month - that is, from the 6t h of one month to the 5t h of the next. Returns will include details of
If, by the due date, ETMP does not receive either: a CIS charge notification that a CIS nil return has been submitted a CIS signal indicating no return is due ETMP calculates a specified amount for that month based on the average amount due on the CIS charges received. CIS specified charges are raised under the provisions of Regulation 11 of the Income Tax (Construction Industry Scheme) Regulations 2005. If no CIS returns have been received during the tax year, the specified amount is calculated
A contractor who engages subcontractors and is required to make deductions from payments made under the Construction Industry Scheme (CIS) is also required to submit monthly returns on form CIS300. Deductions included on these monthly returns and paid over to HMRC are accounted for at the year end through BROCS, see CISR69010 onwards for further details. This is an accounting process only and the relevant returns are the forms CIS300. CIS deductions are made on account of the subcontractor’s inc
Prior to April 2015, contractors must make nil returns if they make no payments to subcontractors in the month under CIS regulations. From 6 April 2015 contractors that have not made any payments under a construction contract are no longer obliged to submit a nil return to HMRC. After 6 April 2015, if contractors do not make any payments to subcontractors in a tax month they must still notify HMRC in order to avoid a CIS late-filing penalty notice and a CIS-specified charge. Ask the contractor t
One of the strategic aims of CIS is to reduce the regulatory burden on the construction industry. This has been achieved in part, by the removal of the voucher paper trail used in the old scheme up to 5 April 2007. But we still need to know about the payments made by contractors to their subcontractors. So, from 6 April 2007 CIS places an obligation on Contractors to make a monthly return. Every contractor who makes payments to subcontractors in respect of construction operations must send a sin
From 2007-08 onwards annual returns of payments to subcontractors will no longer be required. Instead, every contractor who makes payments to subcontractors in respect of construction operations must send to HMRC every month: a return CIS(300) with details of what has been paid to subcontractors in the month any deductions made from those payments. The outstanding returns will move into IDMS on or around the 29th of the month. Once the outstanding returns are received in IDMS they are visible on
| CISR67000 | Information contents | |—————————————————————————————————–|———————-| Inactivity can be requested in the following ways By ticking box 8 on page 4 of a paper-based contractor’s monthly return By checking the relevant box under the declarations section of a return filed electronically By telephone By correspondence This section concentrates on requests for inactivity that are made by return. See CISR67640 for details of what to do when requests are first made by telephone or are in w