Gas Safe9 June 2026· 7 min read

Gas Safety Certificate Invoice UK: How to Charge for CP12 & Landlord Certs (2026)

Gas safety certificates are a significant and reliable revenue stream for Gas Safe registered plumbers — especially if you build a landlord client base. Here is how to invoice for them correctly, what to charge, and how to do it all in seconds from your phone.

CP12 vs Gas Safety Record

The terms CP12 and Gas Safety Record (GSR) refer to the same document — the official record of a gas safety inspection issued under the Gas Safety (Installation and Use) Regulations 1998. CP12 was the legacy form reference; Gas Safety Record is the current official term. Landlords are legally required to have a valid GSR for each tenanted property and to renew it every 12 months.

How Much to Charge for Gas Safety Certificates

UK Gas Safe engineers charged the following typical rates in 2026. Prices vary by region, number of appliances, and whether the inspection is standalone or combined with other work.

ServiceRest of UKLondon
Standard landlord gas safety check (1 boiler, 1 appliance)£60–£95£85–£120
Standard check + additional gas fire£75–£115£100–£145
Standard check + gas hob£75–£110£95–£140
Full property (boiler + 3+ appliances)£95–£150£130–£200
Commercial property — up to 5 appliances£150–£300£200–£400
Emergency gas safety check (same day)+50–100% premium+50–100% premium

Many Gas Safe engineers combine the annual check with a boiler service, charging £80–£180 for the combined visit. This is often better value for the landlord and a better hourly rate for you.

What to Include on the Invoice

A gas safety certificate invoice has a few requirements beyond a standard invoice:

Required

Your Gas Safe registration number

Displayed prominently — customers should be able to verify it at www.gassaferegister.co.uk

Required

Property address inspected

This is the property that was inspected — it may differ from the billing address (landlord's own home or business address).

Required

Description of appliances inspected

List each appliance inspected: 'Gas Safety Record — Worcester Bosch 30i boiler, 1 x gas hob'

Recommended

Gas Safety Record reference number

The certificate serial number from your Gas Safe paperwork. Helps the landlord cross-reference.

Recommended

Pass/advisory note status

Brief indication of outcome: 'All appliances inspected — passed' or note any advisory/defect items.

Required

Standard invoice elements

Invoice number, date, your business name and address, customer name and address, payment due date, bank details.

Example Gas Safety Certificate Invoice

GAS SAFETY INVOICE

Dave Smith Plumbing & Heating

Gas Safe Reg: 654321

Invoice: INV-0087

Date: 9 June 2026

Invoiced to:

Mr James Porter (Landlord)

44 Maple Street

Manchester M16 0AB

Property inspected: 12 Birch Close, Manchester M14 5BX

Annual gas safety record — Worcester Bosch 30CDi boiler£75.00
Additional appliance — Baxi gas fire in living room£20.00
Total due£95.00

GSR reference: GS-2026-88432 · All appliances passed · Certificate issued separately

Payment due: 16 June 2026 · Bank: Dave Smith · 12-34-56 · 87654321

Building a Landlord Client Base

Landlords with gas safety certificate obligations represent guaranteed, recurring annual revenue. A landlord with 5 properties is worth at least 5 gas safety visits per year — plus boiler services and any remedial work identified.

Remind them automatically

Set up a reminder system (even a simple note in your calendar) to contact each landlord 6 weeks before their certificate expires. Being proactive keeps the job with you rather than them shopping around.

Offer an annual service package

Bundle the gas safety check, boiler service, and a minor maintenance call for a fixed annual price. Landlords love predictable costs.

Contact local letting agents

Letting agents manage hundreds of rental properties and are always looking for reliable Gas Safe engineers. One good agent relationship can be worth 30–50 certificates per year.

Keep digital records for each property

Knowing the make, model, and age of every appliance at each property lets you do the job faster and spot potential issues before they become urgent callouts.

Annual Renewal and Reminder Service

One of the most effective things you can do for your gas safety business is build an annual renewal workflow. Each certificate issued becomes a recurring booking for next year.

On each gas safety invoice, include the expiry date of the certificate issued and a note that you will contact them 6 weeks before renewal. This simple commitment, if you follow through, eliminates the need for landlords to remember their compliance obligations and cements your relationship with them.

TraderInvoice lets you create a gas safety certificate invoice by voice — just mention the property address, appliances inspected, your Gas Safe number, and the amount. The invoice is formatted and sent before you have packed up your tools.

Invoice every gas safety job before you leave the property

Speak your gas safety invoice in 30 seconds. TraderInvoice formats it with your Gas Safe number, property address, and appliances. Free for 5 invoices/month.

Frequently Asked Questions

How much should a Gas Safe engineer charge for a CP12 certificate?

UK Gas Safe engineers typically charge £60–£120 for a standard domestic landlord gas safety check (CP12 / Gas Safety Record) covering one boiler and up to two other appliances. London and the South East tend to be at the higher end of this range. Additional appliances (gas fires, gas hobs, second boiler) add £15–£30 each. Properties with multiple gas appliances or requiring remedial work before certification can cost significantly more. The certificate itself (the Gas Safety Record document) is issued at no additional charge beyond the inspection fee.

What must be on a gas safety certificate invoice?

In addition to standard invoice elements (your business name, invoice number, date, customer details, bank details), a gas safety certificate invoice should include: your Gas Safe registration number, a description of each appliance inspected, the address of the property inspected (which may differ from the invoice recipient), whether each appliance passed or had advisory/defect notices, the Gas Safety Record reference or serial number, and whether the annual reminder service applies.

Do I need to send both an invoice and a Gas Safety Record to a landlord?

Yes — these are two separate documents. The Gas Safety Record (CP12) is the official certificate you complete via the Gas Safe Register — it records the inspection results and is the legal compliance document that landlords must give to tenants within 28 days. Your invoice is a separate commercial document requesting payment. Many Gas Safe engineers issue both documents at the same time for efficiency.

Can I charge VAT on gas safety certificate work?

Yes, if you are VAT-registered. Gas safety inspections are standard-rated services and VAT at 20% applies to the full invoice amount. If you are not VAT-registered (turnover below £90,000), you charge no VAT. Your Gas Safe registration number should appear on VAT invoices.