CIS resources for bookkeepers and contractors

Plain-English guides to the Construction Industry Scheme — deductions, rates, filing the CIS300 and choosing a tool — plus a free deduction calculator.

Free tools

Tool

Free CIS deduction calculator

Enter labour, materials and the rate — get the deduction, net pay and the figures you need for the CIS300. No sign-up.

Read →

Guides

Guide

How CIS deductions work

Who deducts from whom, the 20/30/0% rates, the labour-only rule, a worked example and the CIS300 deadline — the complete guide.

Read →

Guide

CIS deduction rates explained

20% verified, 30% unverified, 0% gross status — what each means, how HMRC verification sets the rate, and worked examples.

Read →

Guide

How to file a CIS return (CIS300)

The 19th deadline, what you need, the step-by-step, nil returns, common mistakes, and the £100→£200 penalty ladder.

Read →

Guide

CIS invoice software, explained

The manual pain, what to look for in a tool, and how automated extraction turns invoices into HMRC-ready CIS bills.

Read →

FAQ

CISflow FAQ

Honest answers on CIS basics, data safety, who owns the figures, Xero and QuickBooks support, accuracy and pricing.

Read →

Stop typing CIS invoices

CISflow reads a subcontractor invoice and extracts the CIS fields for you to review and approve, then drops a clean CIS bill into Xero. Live, with a 14-day free trial.

Start free Try the calculator