AI Invoice Generator.
Invoicing for gas engineers.
Service, repair or emergency callout - describe the job in one sentence and the invoice writes itself, parts and labour itemised, VAT exact.
No signup, no card needed to try it.
Say it like you would say it
"Invoice Mrs Hart 320 for the boiler repair: callout 60, labour 120, new diverter valve 140, due in 7 days"
That is the whole job. The AI writes the lines, deterministic code does every sum in exact pence, and the invoice is ready to send with your logo on it.
Service season does not wait
Forty boilers serviced, forty invoices owed
When the heating season starts, the work stacks up faster than the paperwork - and the paperwork is where the money is.
The autumn pile-up
September to December is back-to-back services and breakdowns. Every invoice you defer to Sunday night is money idling a week behind the work.
Landlords with portfolios
Agents and landlords want one invoice per property, itemised, on their terms. Saved customers make the fifth invoice to the same agent a one-liner.
Emergency jobs, invoiced late
The 9pm no-heat callout gets fixed fast and invoiced never. The van is where the details are freshest - and where the invoice should happen.
Instant professional templates
Send something that looks like you charge properly
An invoice that looks thrown together gets treated like one. Pick from 26 designs - these are the real ones, not pictures of them - and switch at any point, before or after you have written it. Your logo and colours go on top.
Luxury
Tradesman
Luxury Gold
Why your accountant can relax
The AI writes. It does not count.
Language models are good with words and unreliable with arithmetic, so DocMason only lets them do the first part. Every figure on a document you send is worked out by ordinary code, in exact pence, the same way every time.
It is the difference between a tool you check afterwards and one you can send without reading twice.
- VAT, discounts and totals calculated in code, never by the AI
- Money held in exact pence, so rounding cannot drift
- Every email sent on your behalf is stored in full, so you can read exactly what went out and to whom
- Your data hosted in the EU, never used to train AI models
FAQs
Questions from gas engineers, answered straight
The free tier, the maths, and how invoicing fits the way gas engineers actually work. Everything else is on the full page.
Something else on your mind? Ask a human.
I invoice the same letting agents constantly - is that quick?
Yes. Agents and landlords save to your address book, so a per-property invoice is one sentence with their details filling themselves in - and the property in the line item. The dashboard then tracks who still owes what.
Does it produce gas safety certificates?
No, honestly - DocMason invoices the work, it does not generate CP12s or other gas safety paperwork. Keep issuing certificates the way you do now; what changes is that the service visit is invoiced from one sentence before you leave the kerb.
Is it really free?
Yes. Build and preview an invoice with no account at all, and create a free account when you want the PDF. The free plan includes 3 invoices and 3 quotes every month with all 26 designs - no card needed. Starter at 9.99 GBP a month makes them unlimited.
Does the AI do the maths?
No, and that is deliberate. The AI reads what you typed; plain deterministic code computes every total, discount and VAT figure in exact pence. AI is good at language and bad at arithmetic, so it only does the first one.
Want the whole picture? See everything the invoice generator does.
Your next invoice takes a minute
3 free invoices a month. Describe the job like you would say it, and see for yourself.