FAQ

Questions, answered straight

How CIS works, how CISflow handles it, and the honest answers on data, accuracy and accountability.

What is the Construction Industry Scheme (CIS)?

CIS is HMRC's tax scheme for the construction industry. When a contractor pays a subcontractor, they must deduct tax from the labour part of the payment and pass it to HMRC on the subcontractor's behalf. Each month the contractor files a CIS300 return summarising those payments and deductions.

How does the CIS deduction actually work?

The deduction comes off the labour element only — materials are exempt. The rate depends on the subcontractor's status: 20% if they're registered (verified) with HMRC, 30% if they're not verified, and 0% for subcontractors with gross-payment status. So on an invoice you split labour from materials, apply the right rate to the labour, and the rest is paid to the subcontractor.

When is the CIS300 return due?

The CIS300 monthly return is due by the 19th of each month, covering the tax month that ended on the 5th. Filing or paying late triggers HMRC penalties — starting at £100, rising to £200 at two months and climbing from there — which is why beating the 19th matters.

Are materials really exempt from the deduction?

Yes. The CIS deduction applies to labour only. Genuine materials costs the subcontractor has paid for — and any VAT — are excluded from the amount you deduct from. Getting the labour/materials split right is exactly the bit CISflow extracts for you to check.

What does CISflow do?

You forward a subcontractor invoice and CISflow reads it, pulling out the CIS fields — UTR, verification number, labour/materials split, deduction rate, deduction amount and net pay. It shows them to you to review, then on your approval drops a clean, HMRC-ready CIS bill into Xero or exports CSV for your CIS300 and bookkeeping.

How accurate is the extraction?

It's good, but it is not a substitute for your eyes — and we don't pretend it is. That's the whole point of the review-and-approve step: every extracted figure is laid out for you to check and correct before anything posts. You catch anything the model gets wrong, so a misread never reaches your books.

Who is responsible for the figures?

You are — by design. CISflow is a data-entry tool, not an accountancy or tax service. You review every extracted field and approve it before anything is posted, and you remain responsible for everything submitted to HMRC. We kill the typing; the figures stay yours to own.

What kinds of invoice can it read?

PDFs, email attachments, scans and photos. If you can forward it as an email attachment, CISflow can have a go at reading it — including messy, hand-typed layouts. You always review the result before it's used.

Does it work with Xero?

Yes — native Xero write-back is the first integration, dropping an approved CIS bill straight into Xero so you're not re-keying it there either. Xero App Store certification is targeted for launch.

Does it work with QuickBooks or other software?

CISflow exports clean CSV that imports into any accounting package, so it works alongside QuickBooks, Sage, FreeAgent and others today. Native QuickBooks write-back follows the Xero integration.

Is my client data safe?

Your account and the extracted CIS records are encrypted, stored in our UK-region (London) database under UK GDPR, and isolated to your own account so no one else can read them. To read the figures off an invoice, the invoice content is sent to OpenRouter — a US-based AI provider — for the extraction step, which we disclose openly. Our privacy page has the full detail: what we collect, our sub-processors, what's retained and your rights.

What happens to my documents after processing?

The raw uploaded file isn't kept as an archive — it's used for the extraction step and not retained long-term. The extracted CIS fields stay in your account so your statements and CIS300 work; you can delete that data by deleting your account.

Do you have ISO 27001 or Cyber Essentials?

Not yet, and we won't claim a certification we don't hold. Both are in progress and targeted before a wider launch. ICO registration and a written data-processing agreement are also still on our to-do list — we say so plainly rather than imply they're already in place. What is in place today: encryption, UK-region storage, and account-level data isolation.

What does CISflow cost?

Two plans: Solo at £39/mo for a single bookkeeper or contractor, and Practice at £99/mo for running CIS across multiple contractor clients with multiple team members. Both start with a 14-day free trial and need no card to begin.

Can I cancel anytime?

Yes. There's no contract or notice period — cancel from your account whenever you like and you keep access until the end of the period you've paid for. The free trial means you only ever pay once you've decided CISflow is worth it.

Still have a question?

Email us — a real person replies. Or send a sample invoice and watch CISflow read the CIS fields back to you.

Or email hello@cisflow.app