Best gas certificate apps for UK engineers (CP12)

A gas certificate app has to do two things well: produce a record that meets HSE rules every time, and get it to the landlord fast. We compared the main UK CP12 apps on forms, devices, reminders and price, using pricing pages and HSE guidance checked on 12 October 2026.

What must a gas safety record include (HSE)?

The Gas Safety (Installation and Use) Regulations 1998 set what a landlord gas safety record must contain. According to HSE, the minimum is:

• a description and the location of each appliance or flue checked;
• the name, registration number and signature of the person who did the check;
• the date of the check;
• the address of the property where the appliance or flue is installed;
• the name and address of the landlord, or their agent;
• any safety-related defect found and any remedial action taken;
• confirmation that the check covered the matters set out in regulation 26(9) of the 1998 Regulations.

HSE adds three points that matter when you pick software:

• Registration. A record issued after 1 April 2009 is only valid if the engineer is registered with Gas Safe Register. Your app should store and print your registration number automatically.
• Completion. The record should only be issued once all the required checks are complete. Apps that block sending until every mandatory field is filled help here.
• Electronic records. They are fine if they can be printed on request, are secure from loss and interference, and identify the engineer (for example an electronic or scanned signature, registration number or name).

How do the gas certificate apps compare?

Standalone certificate app or full job management?

This is the first decision, and it matters more than which brand you pick. A standalone certificate app does one job: it produces gas records quickly and sends them. A job management app adds quotes, scheduling, invoicing and payments, with certificates as one part of the job.

A worked example: the gap between Gas Engineer Software Starter (£216 a year ex VAT) and Powered Now Professional (£320 a year ex VAT) is £104 a year, or £2 a week. If you already pay for separate quoting or invoicing software, add that cost to the standalone app before comparing, and remember that two systems mean typing every customer's details twice. If you only issue certificates for letting agents who pay on account, the standalone app is the cheaper, simpler choice. If you quote boiler swaps and repairs as well, the job management app usually pays for itself in saved admin time.

Gas Engineer Software: best value for sole engineers

Gas Engineer Software (GES) is built for gas engineers first. The Starter plan costs £18 a month billed annually or £19 monthly, ex VAT, and Pro costs £30 per user a month. It covers CP12s, boiler service records, gas and oil certificates, heat pump certificates and job sheets, with offline apps for Android and iOS and a web portal for the office. There is a 14-day trial with no card.

Two cautions. The pricing page contradicts itself on the middle Core plan (£23 per user in the FAQ, £25 in the calculator). And warning notices and commissioning forms are not named on the pricing page, though it claims "all standard gas industry certificates". Confirm both in the trial.

Pick it if you are a sole engineer doing mostly landlord checks and services. Skip it if you need strong quoting and scheduling as well.

Gas Certificate App: widest form list

Gas Certificate App, from Trade Apps Ltd, has the broadest certificate range of the standalone apps: domestic CP12, breakdown, service, warning notice, boiler commissioning checklist, unvented cylinder, non-domestic, commercial, LPG, leisure and catering records, CP15 test and purge, oil forms (CD/10 to CD/51 and TI/133D), power flush, heat pump commissioning, and even caravan and boat records. It costs £20 per user a month or £216 a year ex VAT on its own site. Through the App Store it is £20.49 a month or £224.99 a year, so buying direct is slightly cheaper.

It has 4.2 from 232 ratings on the UK App Store, checked 12 Oct 2026, and offers a 14-day trial with no card.

Pick it if you do commercial, LPG, catering or oil work alongside domestic gas. Skip it if you want invoicing in the same app.

iCertifi GasCert: for iPhone users already on iCertifi

iCertifi GasCert costs £24.99 a month or £149 a year, with an Enterprise plan at £490 a year, and iCertifi says its prices include VAT. Once you account for VAT, the £149 annual plan is competitive with the ex-VAT prices of the apps above. It covers CP1, CP12, breakdown and service reports, warning notices, service and maintenance records, non-domestic test and purge, and leisure industry records. No commissioning form is listed.

The App Store listing needs iOS 18.6 or later. It had only 2 ratings on the UK App Store when we checked, so there is little user feedback to judge it on. There is a 2-week trial.

Pick it if you already use iCertifi for electrical work and want the same company for gas. Skip it if you install boilers and need commissioning records.

Powered Now: best for certificates plus MTD

Powered Now is a UK-built job management app with nearly 100 trade forms, and its gas set is extensive: CP12, breakdown and service records, service checklist, warning notice, test and purge, central heating commissioning, power flush, CP2 leisure, non-domestic safety report, plant commissioning, catering, unvented hot water, water pipework and bonding notice. Certificates come with automatic annual reminders, which is the feature that turns one landlord check into a yearly customer.

Certificates need the Professional plan at £32 per user a month ex VAT (£320 a year). The £28 Business plan does not include them. Powered Now is also recognised by HMRC for MTD for VAT and Income Tax, and runs on Mac and Windows as well as phones. Its App Store score is lower than some rivals (4.1 from 243 ratings), but Trustpilot shows 4.7 from 564 reviews, both checked 12 Oct 2026. Read our full Powered Now review.

Pick it if you want certificates, quotes, invoices and tax in one UK app at a low price.

Tradify: best all-rounder for small gas and heating teams

Tradify is our best overall pick for small UK trade teams, and its gas coverage is strong: landlord and homeowner gas safety records, service and maintenance records, install, commission and decommission records, warning notices, breakdown reports, catering, central heating commissioning, unvented hot water, test and purge and boiler records, plus oil forms CD/10, CD/11, CD/12, CD/14 and TI/133D. Certificates start on the Pro plan at £37 per user a month. Service reminders need Plus at £44.

You also get quoting, scheduling, timesheets and invoicing, with Xero, Sage and QuickBooks on every plan, and Trustpilot 4.8 from 610 reviews (checked 12 Oct 2026).

Try Tradify free (Ad) Read our Tradify review

Commusoft and Joblogic: for bigger firms

Once you have office staff dispatching several engineers, a standalone certificate app stops being enough. You need shared scheduling, service contracts and a single record of every appliance across hundreds of properties.

Commusoft focuses on plumbing and heating firms with 6 or more staff. It does not publish prices (Capterra UK lists it from £59 per user), prices exclude VAT, and contracts run 12 months billed monthly. Its engineer app works offline with custom forms and digitised certificates, and it manages service contracts and recurring maintenance. See our Commusoft review.

Joblogic has a long gas form list too, including CP17 non-domestic, CP42 catering, RIDDOR warning notices and mains pressure cylinders, plus custom templates. Standard costs from £45 per user a month billed annually, and most customers sign 24 or 36 month contracts. Its iPhone app is rated 1.8 from 201 ratings, so trial the engineer experience carefully.

For a wider look at running a heating business, including costs for a five-person team, see our guide to software for gas and heating engineers. If you mainly do plumbing, read our plumbing software guide.

Landlord rules: annual check, 2-year records, 28 days to tenants

Landlord work drives most CP12s, so your app should make these deadlines easy to hit. According to HSE:

What this means for your software: send the PDF from site the moment the check is done, keep every past record searchable for at least two years, and set reminders about ten to eleven months after each check so you can book the next one inside the 2-month early window.

Not found: we searched for "Gaspack" and "Easy Gas Certs" and found no matching UK product, so we have left them out.