CIS monthly return: deadlines, how to file in Xero and QuickBooks, penalties and nil returns

• Jump to: Who this is for • Quick answer • CIS timeline • File in Xero • File in QuickBooks • Nil return or inactivity • Send statements • Pay HMRC • Common errors • Checklist • Helpful links • FAQ

Who this is for

Construction contractors and firms that pay subcontractors under the Construction Industry Scheme. If you pay any subbies for labour, you must file a CIS300 monthly return to HMRC, even if the total is zero for that month.

Quick answer

• CIS tax month runs from the 6th to the 5th.
• File your CIS300 monthly return by the 19th of the following month.
• Pay the CIS deductions to HMRC with your PAYE by the 22nd if paying electronically.
• If you paid no subcontractors, file a nil return or request temporary inactivity to avoid penalties.

Sign in to the CIS online service and HMRC’s guidance on filing monthly returns explain the official rules.

CIS timeline at a glance

File the CIS300 in Xero step-by-step

Before you start

• Make sure you are registered as a CIS contractor and have your PAYE reference and Accounts Office reference.
• Enable CIS in your UK Xero organisation. Verify all new subcontractors with HMRC and set their CIS rate on their contact.

Steps each month

1. Enter subcontractor bills with CIS

• Split labour and materials so CIS is only calculated on labour. Add verification if prompted.

1. Review the CIS Contractor report

• Go to Accounting, Reports, CIS Contractor (Monthly Return, Online Filing and Statements). Select the tax month and review totals. Drill into lines to fix coding.

1. Submit to HMRC

• From that report, use the submit option to file the CIS300 directly to HMRC. Save the receipt/correlation ID.

1. Send CIS statements

• From the same area, generate and email payment and deduction statements to each subcontractor within 14 days of month end.

Helpful context

• HMRC guidance on verifying subcontractors.
• Xero’s CIS enhancements overview: Achieve greater speed and accuracy with CIS in Xero.

File the CIS300 in QuickBooks Online step-by-step

Before you start

• Turn on CIS: Settings, Account and settings, Advanced, Construction Industry Scheme.
• Set up each subcontractor as a Supplier with UTR and CIS rate. Tick materials on bill lines that should not be subject to CIS.
• Connect QuickBooks to HMRC for CIS e-Submission.

Steps each month

1. Prepare the return

• Taxes, CIS, pick the period (6th to 5th). Review each subcontractor’s totals. Verify any not yet verified with HMRC.

1. Submit to HMRC

• Answer the declaration questions and submit. Save the receipt/correlation ID.

1. Send CIS statements

• From the supplier or CIS area, generate and send payment and deduction statements to each subcontractor.

If you paid no subcontractors: nil return or inactivity request

• You must still tell HMRC there were no payments. File a nil return for that tax month.
• If you expect several quiet months, you can request up to 6 months’ inactivity so HMRC does not expect a return during that period.