The Construction Industry Scheme (CIS) requires contractors to deduct tax from subcontractor payments and file monthly returns with HMRC. Even if no payments are made, nil returns must be submitted to avoid penalties.

The CIS is a specialised set of rules governing tax and national insurance for individuals working within the construction industry. This scheme specifically applies to businesses operating as 'contractors' and 'subcontractors' within the construction sector. Under the provisions of the scheme, contractors are required to deduct money from a subcontractor’s payments and pass it to HMRC. The deductions count as advance payments towards the subcontractor’s tax and National Insurance.

One of the primary responsibilities for contractors under the CIS is the submission of monthly returns, which must be completed and filed online. These returns correspond to each tax month, which runs from the 6th day of one month to the 5th day of the following month. The deadline for submitting these returns is 14 days after the conclusion of each tax month.

It is important to note that even if no subcontractors have been paid during a particular tax month, contractors are still required to file a 'nil return.' The necessity to submit returns must be met regardless of whether the contractor typically submits PAYE returns on a quarterly basis. Contractors can file their monthly returns using the HMRC CIS online service or through commercial CIS software. Failure to submit the required returns on time may result in penalties and interest charges.

In cases where a contractor has not made any payments to subcontractors during a given tax month, they are still obligated to submit a 'CIS nil return' or inform HMRC that no return is necessary. Should this 'nil return' situation become a long-term occurrence, contractors have the option to request a period of inactivity from HMRC. This request indicates that the contractor has temporarily ceased employing subcontractors and lasts for a period of six months. It is important to notify HMRC if subcontractor payments resume within this time frame, as this could affect the contractor’s obligations under the scheme.

Contractors are defined as those who make payments to subcontractors for construction work or who have spent more than £3 million on construction in the 12 months following their first payment under the scheme.