Yes — a payment and deduction statement for every subcontractor you deducted from, within 14 days of the end of the tax month. It must show your details, theirs, the gross payment, the cost of materials, and the amount deducted. Subcontractors need it to prove what was taken, so failing to issue one leaves them unable to reclaim correctly and creates a dispute you will have to resolve later anyway. Gross payment status subcontractors need no statement, since nothing was deducted. Keep copies: if HMRC reviews your CIS operation, the statements are how you evidence what you did. Most software generates them from the return automatically, which is the easiest way to make sure it happens on time rather than when someone chases.