CIS invoice processing for bookkeeping practices

The monthly CIS job, as a practice actually does it

For a bookkeeping practice with a few construction clients, CIS isn't a once-a-year task — it's a monthly grind that peaks in the run-up to the 19th. Across all your CIS clients, the same cycle repeats:

1. Subcontractor invoices arrive — PDFs, scans, the odd phone photo — through the month.
2. For each one you separate labour from materials, strip VAT, and confirm the subcontractor's rate (20%, 30% or 0%).
3. You re-key the figures into each client's Xero, Sage or QuickBooks as a CIS bill.
4. You reconcile the month's deductions, prepare the CIS300, and issue each subcontractor a payment and deduction statement (PDS).
5. You file before the 19th and pay the deductions over to HMRC.

Multiply that by every CIS client, and the bottleneck is obvious: it's the keying. The filing is quick once the figures are right — getting the figures off the invoices and into the books is what eats the days before the deadline.

Why keying every subbie invoice is the real pain

The manual entry isn't just slow — it's where the risk lives. Each invoice is a chance to mis-split labour and materials, apply the wrong rate to an unverified subcontractor, or fat-finger a figure that then flows straight onto a client's CIS300. And it all clusters into the same few days each month.

• It scales with clients, not effort. Ten subbie invoices across three clients is thirty separate read-split-rekey jobs.
• It's deadline-shaped. The work bunches before the 19th, exactly when the practice is busiest.
• Errors are expensive. A wrong split or rate means an incorrect deduction — a real HMRC exposure, and a late correction is worse.
• It's low-value typing. Skilled bookkeeper time is going on data entry, not on advising the client.

The labour/materials split alone is the most common CIS error — there's a full walkthrough in how to split labour and materials on a CIS invoice.

How CISflow fits the practice workflow

CISflow doesn't replace your accounting software or your CIS process — it removes the slowest, riskiest step: getting the figures off each invoice. The flow is deliberately simple, and you stay in control at every stage:

1. Read. Forward a subcontractor invoice — PDF, scan or photo — and CISflow extracts the CIS fields: UTR, the labour/materials split, the rate, the deduction and the net.
2. Review. Every figure is laid out for you to check and correct. Nothing posts silently — your eyes are always the last step.
3. Approve. Once you're happy, you approve the bill. Not before.
4. Export. CISflow writes a clean, HMRC-ready CIS bill into the client's Xero, or exports CSV for QuickBooks, Sage and others.
5. PDS & CIS300. You've got clean per-subcontractor figures to issue payment and deduction statements and prepare the monthly CIS300 return.

The job that used to be read-split-rekey for every invoice becomes read-review-approve — the typing is gone, but the judgement stays with you. For the wider picture of what to look for in a tool, see CIS invoice software, explained.

You own every figure

This is the part that matters most for a practice: your name is on the return, so the tool can never be a black box. CISflow is built around that. Every extracted figure is presented for your review before it becomes a bill; nothing is filed, verified or posted without you. CISflow is a data-entry accelerator, not an accountant — it speeds up the typing and leaves the responsibility, and the judgement, exactly where they belong: with you.

It also doesn't do the things that aren't its job: it doesn't file the CIS300, doesn't verify subcontractors with HMRC, and doesn't replace your accounting software. It hands you clean figures to work with — you do the rest, the way you always have.

Being honest about where CISflow is

CISflow is new and in early access. We'd rather you knew that up front:

• It handles CIS subcontractor invoices only — not general receipts or bank statements.
• You review and correct every figure; extraction is good, but it is not a substitute for your eyes.
• It does not file or verify with HMRC — you remain responsible for what reaches the return.
• It's young: fewer integrations and less track record than long-established tools.

If your practice does enough CIS that the monthly keying is a genuine bottleneck, that's exactly where CISflow earns its place. If CIS is a small corner of your workload, the free calculator below may be all you need today.

Want to test it on a real client's invoice before committing anything? Try the free CIS deduction calculator first to feel the split and the rates, then start free to run an actual subbie invoice through CISflow and check the extracted figures yourself.

This page is general information for UK bookkeeping practices, not tax advice. Always verify a subcontractor's status and rate with HMRC and check the figures before they reach a client's return. CISflow is a data-entry tool, not an accountancy or tax service — you remain responsible for figures submitted to HMRC.