For UK plumbers
Built for plumbers. Compliant invoices in 30 seconds.
Voice-to-invoice for UK sole-trader plumbers. Talk through the boiler commissioning, the 11pm burst-pipe callout, the bathroom refit — Honest Invoices builds the invoice, keeps a clean trail to your benchmark commissioning certificate, and reconciles emergency cash jobs against the bank without an evening at the kitchen table.
What you say
“Boiler service at 14 Acacia Road — full strip and clean, replaced the expansion vessel, no warning notice. Ninety minutes on site. Ninety quid for labour, forty-two for the vessel.”
What Honest Invoices does in 30 seconds
- · Extracts time, materials and costs from the words you used
- · Builds a compliant UK invoice with sequential numbering, VAT (if registered), and your payment terms
- · Stores the digital record for MTD ITSA quarterly submission
- · Emails the PDF to your client when you tap send
£15/month, locked · 14-day free trial · no card required
The reality
The pain you actually have.
Generic accounting software is built for accountants. This is built for a plumber who finishes a job at 5pm covered in dust and just wants to get paid.
01
Boiler services and emergency callouts get invoiced in the van or never. By 8pm at home, the day is gone and the paperwork starts piling up.
02
CIS deductions get taken at 20% off your commercial work, but most jobbing plumbers have no clean running total of what they're owed back at year-end.
03
Boiler service intervals get jotted on the back of a job ticket then lost in the van. Meanwhile the £180 emergency callout you took in cash at 11pm needs reconciling against the bank deposit you made three days later — and by January that pairing has gone cold.
Got an HMRC question?
Ask HMRC is a free, grounded-in-gov.uk assistant that knows what matters to plumbers — CIS, trade registration fees, VAT rules and the rest. Five questions a day, no signup, no card.
Try this one
“Do I need to register for VAT at £8,000 a month turnover?”
What it does
Three things. Built for trades.
No bloat, no “multi-entity reporting”.
Voice-to-invoice that speaks plumber
Describe a boiler service, a tap swap, a soil-pipe replacement, a bathroom refit, in the words you actually use on the phone to the customer. The AI extracts the time, the parts, the customer name, and builds a UK-compliant invoice with sequential numbering, your business details, and your payment terms.
No typing on a tiny phone keyboard between jobs. No remembering what you did Monday on Friday.
Benchmark commissioning records — the bit beyond the CP12
A landlord CP12 is the certificate everyone has heard of. The Benchmark commissioning sheet that goes with a new boiler — and the Gas Warning Notice you issue when an appliance is At Risk or Immediately Dangerous — get less attention and more often go missing. Honest Invoices keeps every Gas Safe document referenced against the job and the invoice: commissioning cert number, warning notice serial, appliance model and serial. When a landlord asks for proof, when a manufacturer wants a warranty registration confirmed, when HSE knocks — your paperwork trail is one search, not a glove-box hunt.
CIS labour-and-materials split, automatic
When you're sub-contracting on commercial sites under CIS, every invoice needs labour and materials shown separately — otherwise the contractor deducts CIS on the whole lot, including the £600 you spent at Plumb Center.
Most plumbers split their time between domestic callouts (no CIS — paid gross) and commercial sub-work routed through a main contractor (CIS deducted at 20% or 30%). Honest Invoices flags each invoice with its CIS status at creation, runs the labour/materials calculation only where it actually matters, and keeps your year-end reclaim figure ready for the accountant without a December evening sorting Payment and Deduction Statements into piles.
MTD-ready records, built end-to-end against HMRC
Every job you record — boiler service, emergency callout, bathroom refit, landlord round — is a digital record in the format HMRC’s MTD ITSA APIs expect. Quarterly updates and BSAS are fully tested in HMRC’s sandbox environment (16/16), with production approval in progress — they go live to users the moment our production credentials land. Final Declaration support is planned for the following release.
A typical sole-trader plumber sees uneven income — a quiet February followed by a boiler-replacement spike in October. Quarterly figures need consistent record-keeping across that whole shape, not a forensic reconstruction in week one of August. Start digital records today and the first quarter (6 April – 5 July 2026) submits cleanly on 7 August.
From the founder
Built end-to-end against HMRC’s APIs.
Honest Invoices is built and run by Vix Hawley. The MTD ITSA integration was built by hand — OAuth, fraud-prevention headers, the full Self-Employment Business and BSAS APIs. It took months. The full HMRC sandbox journey passes 16 out of 16 steps with proof on file.
Most accounting platforms are built for accountants. This one is built for plumberswho don’t want to spend their evenings doing admin. £15/month. Locked. No price hikes, ever.
FAQ
FAQ for plumbers.
Do you generate gas safety certificates / CP12s?
CP12 landlord gas safety records are in active build. The schema, renewal reminders, and signature flow are in place; the wizard and PDF are next. If you do landlord rounds, that’s where the time savings live — and it’s coming.
Until then, your invoices can reference the CP12 number, the property address, and the date so your invoice trail and your cert trail line up at year-end.
What about CIS deductions on commercial sub-work?
Plumbing CIS has a clean line — domestic boiler servicing, emergency callouts, and direct-to-customer bathroom refits are paid gross. Commercial sub-work on new-build sites, housing-association maintenance contracts, or anything routed through a main contractor is CIS-deducted at 20% or 30%. Honest Invoices flags each invoice at creation and keeps the year’s reclaim figure running automatically.
More on the underlying rules: CIS deductions explained and how to reclaim CIS as a sole trader.
I'm a sole-trader plumber earning £55k. Am I in scope for MTD ITSA?
Yes — from 6 April 2026. A sole-trader plumber on £55k of mixed domestic boiler work and commercial sub-contracting is squarely in the first wave. The first quarter covers 6 April to 5 July 2026, submitting by 7 August. Three more quarters follow, plus an annual submission and a final declaration after year-end.
Honest Invoices keeps your records in the right shape today and will submit directly through HMRC's APIs the moment our production credentials land. You have until 7 August.
Will my price go up in two years?
No. £15/month is the price the day you sign up, and the price you'll be paying in three years. If we launch a higher tier in future, you stay on £15 — locked, in the terms, not just a promise.
We've watched accounting software prices triple over five years. We're not doing that to you.
I do mostly cash-in-hand domestic work. Is this still useful?
Yes — but with a caveat. If your turnover is below £20k a year, MTD ITSA doesn't apply to you yet (April 2028 threshold). Honest Invoices is still useful for chasing payment and keeping records clean. Once you're over £20k it becomes mandatory.
Can I keep using my own bank, accountant, and Gas Safe paperwork?
Yes. Honest Invoices is invoicing + (soon) gas safety records. You keep your existing bank account, your existing accountant (we export CSV for them), and any existing certification tools. We don't try to be everything — we try to be the best at the bits we do.
Talk to a person
Not a chatbot.
If you’ve got a question about whether Honest Invoices fits your trade — call, text, or email. You’ll reach the founder, not a queue.
Ready to stop typing invoices?
14 days free. No card required. £15/month after that — locked, forever.