What GES does well
Gas Engineer Software is made for Gas Safe engineers, and it shows. You fill in and send CP12 landlord gas safety records, boiler service records and warning notices from your phone, offline if there is no signal, with readings taken from a Kane, Anton or TPI flue gas analyser. Every record is kept, and a reminder goes to the customer when their next service is due.
It does quotes and invoices too, with payment reminders, and it syncs with Sage, Xero and QuickBooks. For the compliance side of a gas business it is the right kind of tool, and nothing in Slate replaces it.
Where it stops, by design
GES begins when you are booked and standing at the boiler. Its features page, read on 22 October 2026, lists nothing for phone calls, enquiries or new callers. Its service reminders are valuable, but they reach customers you already have. A homeowner who finds you on Google with no heating and gets no answer is not in GES, and never will be.
Side by side
- Built for
- Gas Engineer SoftwareGas certificates, service records and the jobs around them
- Slate OSThe call you miss, and the job it becomes
- New callers
- Gas Engineer SoftwareNot something it sees
- Slate OSTexted back within seconds in your firm's name
- Existing customers
- Gas Engineer SoftwareAutomatic annual service reminders
- Slate OSOn your board with their history, texts and documents
- CP12s and gas forms
- Gas Engineer SoftwareYes, the heart of it
- Slate OSNo
- Price
- Gas Engineer SoftwarePer user. See GES's pricing
- Slate OS£249 a month, the line, calls and texts included
| Gas Engineer Software | Slate OS | |
|---|---|---|
| Built for | Gas certificates, service records and the jobs around them | The call you miss, and the job it becomes |
| New callers | Not something it sees | Texted back within seconds in your firm's name |
| Existing customers | Automatic annual service reminders | On your board with their history, texts and documents |
| CP12s and gas forms | Yes, the heart of it | No |
| Price | Per user. See GES's pricing | £249 a month, the line, calls and texts included |
What we say about GES is from its own features page, read on 22 October 2026. Check it yourself before you decide.
Using the two together
- Put Slate's office line on your Google profile, Checkatrade and the van, so new callers ring it.
- A call you miss is texted back, and the reply tells you the job and the postcode before you ring.
- Once it is booked, do the certificate in GES as you do now.
Straight answers
- Does Slate OS do CP12s or gas safety records?
- No, and it is not trying to. Keep the tool you trust for certificates. Slate catches the calls and holds the job, the texts and the money side.
- Does GES answer or text back missed calls?
- Not on its own features page, read on 22 October 2026. Its reminders go to customers already on your books.
- What does Slate OS cost?
- £249 a month, one plan. The first 25 firms pay £199 a month for as long as they stay. You get 14 days free from the day you start, and if you are not happy within 14 days of your first payment, you message us and we refund it in full.
Sources
Slate OS gives you an office line that rings your own mobile. When you can’t pick up, the caller gets a text in your firm’s name within seconds, and the job lands on your phone. Quotes, invoices and a diary come with it, for when you want them.