CP12 Landlord Gas Safety Certificates: What's Actually Required (And How to Stop Chasing Them)

If you’re a Gas Safe registered engineer doing domestic lettings work, you already know the drill. Annual gas safety check. CP12 issued. Copy to the landlord within 28 days. Copy to the tenant. Rinse and repeat, times however many properties you’re covering — and if you’re doing this across a portfolio of rental properties for a letting agent, the admin alone can eat a full day a week.

The check itself isn’t the hard part. Most engineers could do a CP12 inspection in their sleep — appliance safety, flue performance, ventilation, tightness testing, the lot. What’s hard is everything around it: knowing which properties are due, chasing landlords for access, getting the certificate to the right inbox before the deadline, and proving you did it all when a tenant complains or the HSE comes knocking.

Let’s get the requirement straight first, then talk about why so many gas engineers are still running this on spreadsheets and WhatsApp reminders in 2026.

What a CP12 Certificate Actually Requires

CP12 is the record produced from a Landlord Gas Safety Check — a legal duty under the Gas Safety (Installation and Use) Regulations, enforced by the HSE. Landlords must have every gas appliance and flue in a rented property checked once every 12 months by a Gas Safe registered engineer, and they need to keep proof.

The certificate itself needs to show:

• Every gas appliance and flue checked at the property, with a pass/fail on each
• Your Gas Safe registration number and licence card details
• Details of any defects found and what you did about them (or advised the landlord to do)
• Date of the check and the date the next one is due
• A copy issued to the landlord within 28 days, and to existing tenants within 28 days of the check — new tenants get it before they move in

None of that is optional, and none of it is negotiable if you fail to produce it. If a landlord can’t show a valid CP12 when asked, they’re in breach — and if something goes wrong with an appliance you should have flagged, the paper trail is exactly what gets pulled apart. So the record has to be accurate, timestamped, and easy to retrieve. That’s the bit that actually catches gas engineers out — not the inspection, the record-keeping.

Why CP12 Renewals Turn Into a Chasing Game

Here’s the pattern we hear from Gas Safe engineers up and down the country: you’ve got 60, 100, maybe 300 landlord gas safety records to manage across a client base, and every single one has a different renewal date. Nobody’s diary works like that.

Picture this — it’s a Tuesday, you’re three jobs in, and a letting agent calls asking why the CP12 on 14 Marsh Lane hasn’t been renewed. It expired last week. You didn’t know because it wasn’t flagged, the tenant didn’t chase because tenants never chase, and now the agent’s annoyed and the landlord’s technically not compliant. Multiply that across a portfolio and you’re spending evenings scrolling back through old jobs trying to work out who’s due and who isn’t.

That’s not a Gas Safe problem. That’s an admin problem — and it’s exactly the kind of job small trade businesses can’t justify hiring a full-time office person for, but absolutely need someone doing.

How Hero AI Keeps Your Landlord Gas Safety Record Straight

This is where Hero365 — your AI staff, or Hero AI for short — earns its keep. Hero AI isn’t Gas Safe software in the sense of replacing your registration or doing the inspection for you (nothing does that, nor should it). What it does is take over the chasing, the scheduling, and the record-keeping so nothing slips through:

• Hero AI tracks every CP12 due date on the board and flags renewals coming up, so you’re booking the next check weeks out instead of finding out it lapsed from an angry phone call.
• Hero AI answers the call when a letting agent rings about access or a missed appointment — 24/7, even when you’re up a loft. Most small trade businesses miss around 40% of after-hours calls; Hero AI answers all of them and gets the job back on the schedule.
• Hero AI drafts the estimate for follow-on repair work straight from your voice note after the check, in under a minute — handy when a CP12 turns up a faulty flue and the landlord needs a quote fast.
• Hero AI routes your day so your renewal-due properties get grouped sensibly instead of you criss-crossing the same postcode three times in a week — about 10-15% less drive time, which on a portfolio of rentals adds up fast.
• Hero AI chases the invoice once the job’s done, so you’re not the one ringing a letting agent’s accounts department for the third time.

None of that touches the inspection or the certificate itself — that’s still you, your gauges, and your Gas Safe card. But the stuff around it, the stuff that turns a straightforward annual check into a logistics headache? That’s the job we built Hero AI to do.

CP12 Software vs Doing It Yourself

Plenty of gas engineers still run their landlord gas safety record entirely off memory and a paper diary. It works, until it doesn’t — until a portfolio grows past about 40 properties and the renewal dates start blurring together.

There’s decent dedicated Gas Safe software out there for managing certificates specifically, and if that’s genuinely all you need, fine. But most gas engineers doing lettings work also need to quote follow-on repairs, invoice letting agents who pay on their own schedule, and answer calls from tenants who ring at odd hours because a boiler’s playing up. Tradify, for example, is solid job management for trades — quotes, scheduling, invoicing — priced per user from £34/month on their Lite plan up to £44/month on Plus. That’s a fair option if you want dedicated job software and are happy running the phone and admin side yourself.

Hero365 takes a different angle: instead of paying per seat for software you operate, you’re hiring an AI member of staff that answers calls, books jobs, chases invoices and drafts estimates without you touching a keyboard. Pricing starts at £19.99/month for the AI Concierge tier that answers and books your calls around the clock — no per-seat charge, no onboarding call, you just hire Hero AI and it’s working.

Getting Your CP12 Admin Under Control

If you’re spending more time chasing landlords for access and letting agents for payment than you are actually testing appliances, something’s backwards. The check is your job. The chasing shouldn’t be.

Start by getting every renewal date onto one board you can actually see — that alone kills most of the late-CP12 problems we hear about. Then look at what’s eating your evenings: is it the phone ringing after hours, the invoices going unpaid for 60 days, or the quotes for follow-on repair work that never quite get sent? Whichever it is, that’s the bit worth handing off first.

We built Hero AI so gas engineers doing lettings work could stop being their own office manager. If you want to see what it looks like on your own board, check the pricing and hire Hero AI in about the time it takes to finish this sentence. Or run the numbers first on the cost calculator — either way, you’ll never miss another call or another renewal date again.