Construction and CIS Accounting: What Contractors and Subcontractors Need to Know
A practical guide to CIS registration, monthly returns, subcontractor verification, CIS deductions, repayment claims, and construction VAT issues.
Last reviewed: 23 June 2026
CIS affects both sides of the job
Contractors may need to verify subcontractors, deduct tax, give deduction statements, and file monthly CIS returns. Subcontractors need to understand deductions suffered and how those deductions are reclaimed or offset.
Monthly routines matter
CIS is easier when subcontractor details, payment dates, materials, labour, and deduction statements are captured as work happens. Leaving it until year end can create PAYE, tax return, and cash flow problems.
Watch construction VAT
Many construction businesses also need advice on the domestic reverse charge, VAT registration, flat rate scheme suitability, and whether supplies are to end users or other VAT-registered contractors.