About the template
What this gas fitter invoice template covers and why it gets paid faster
Gas fitter invoices stall when the Certificate of Compliance is not listed as its own line, or when pipe metres on the invoice differ from the quoted figure without explanation. The template below repeats each line as quoted, with actual pipe metres laid and the COC number issued.
On install completion, the COC is the deliverable that justifies the invoice. State the COC number, the issue date, and the unit installed (brand, capacity, gas type). Clients pay faster when the regulated deliverable is visible on the bill.
What to include
Every gas fitters invoice should have these lines
Use it as a checklist when you build your invoice from scratch, or pull the QuoteGenio template that already has them.
Sample
A real gas fitters invoice laid out properly
A worked example so you can see what a clean, structured version looks like before you write your own.
Invoice sample
Gas geyser install · completion invoice with COC
Bill to
Sipho Dlamini
+1 (555) 320 4427
67 Yarrow Drive, Austin
From
Dlamini Gas Services
+1 (555) 218 6041
11 Industrial Avenue, Cedar Park
Site survey and design
Gas geyser (Bosch 16L, LPG) installed
Copper pipe (actual 8m, as quoted)
Regulator and isolating valve
Flue kit and roof penetration
Install labour (1 day, 2 fitters)
COC issued, certificate #COC-78421, 28 May
Removal and disposal of old electric geyser
Less deposit paid 14 May (40%)
Sample data shown in USD. QuoteGenio supports 40+ currencies and your branded business details, banking, and logo flow through automatically.
Use this template
Build your own gas fitters invoice in 2 minutes
Your business name, logo, and banking details fill in automatically. Send the branded PDF via WhatsApp in one tap.
Avoid these
Common mistakes on gas fitters invoices
The patterns that quietly lose jobs, get queried at payment time, or leave money on the table.
Mistake: COC issued but number not on the invoice
Better: List the COC number and issue date on its own line. Client uses it for insurance and any future certification.
Mistake: Pipe metres differ from quote without note
Better: If the run was longer, issue a variation invoice or note 'pipe actual 12m of 8m quoted, variation approved on day'.
Mistake: Pressure test not documented
Better: State 'Pressure test passed at 60 mbar, 5 minutes, leak-free'. Required record for COC validity.
Mistake: Deposit not shown as negative line
Better: Show 'Less deposit paid 14 May (40%): -$ 2,323'.
Mistake: Old unit disposal omitted
Better: Confirm the old unit was removed and disposed of. Otherwise the client asks for proof weeks later.
Mistake: Certificate of Compliance not flagged
Better: Always state 'COC issued on completion'. Required for insurance and for the customer to claim warranty on any installed appliances.
FAQ
Gas Fitters invoice template questions
Everything gas fitters ask before they switch to a structured invoice.
Unit installed, pipe metres, COC number and issue date, pressure test result, old unit disposal, tax, payment terms, and banking details.
On COC issue. The COC is the deliverable that justifies the bill.
14 days residential. 30 days commercial.
Always. Client uses it for insurance, building inspections, and future certification.
Yes for residential. The COC PDF can attach alongside the invoice PDF in the same message.
Keep the original with the property documents. Required for insurance claims and for selling the property.
Related templates
Other plumbing & water templates
Same hub, different trade and same itemised format, ready to send via WhatsApp.
Plumbing Quote Template
Itemised plumbing quote with call-out, parts, labour, disposal, and tax.
Plumbing Invoice Template
Professional plumbing invoice with itemised lines, payment terms, and banking details.
Gas Fitter Quote Template
Gas fitter quote with pipe run, regulator, flue, Certificate of Compliance, and removal.
Drainage Quote Template
Drainage quote with call-out, jet or rod method, CCTV survey, and manhole work.
Drainage Invoice Template
Drainage invoice with call-out, jet or rod method, CCTV survey, and manhole work.
Testimonials
Trusted by tradespeople
Real gas fitters and other tradespeople use QuoteGenio to quote and invoice in minutes from their phone.
“Emergency call-outs at 2am are the worst time to write a quote. Being able to send something formal from my phone in a minute has saved me more than once.”
David Romano
Locksmith · Toronto
“The WhatsApp sending is a game changer. Most of my clients do not check email, so being able to send quotes instantly helps me get quicker responses.”
Kyle Adams
Electrician · Berlin
“Security quotes with six or seven cameras and zones used to be a nightmare. The line item structure handles it easily and clients understand exactly what they are getting.”
Seán McKenna
CCTV Installer · Cork
From the blog
Guides on writing better gas fitters invoices
Hand-picked posts that go deeper on the topics covered in this template.
How to Send Professional Invoices
A messy invoice is the fastest way to delay your payment. Here is what a professional invoice includes and how to send it so the client pays on time.
5 Ways Tradespeople Can Get Paid Faster
Late payments hurt cashflow more than almost anything else. These five habits help tradespeople get paid on time, every time.
How to Handle Late-Paying Clients (Without Damaging the Relationship)
Late payments are stressful, but how you handle them shapes whether you keep the client. Here's a calm, professional process for chasing what you're owed.
Free forever plan
Start quoting faster. Win more jobs.
Create professional quotes in minutes, send instantly, and stay on top of your work without the admin slowing you down.
Free to start. No credit card required.