The short answer: a landlord's gas appliances and flues must be checked by a Gas Safe registered engineer at least every 12 months. The next check is due 12 months after the last one. You can have it done up to 2 months early and keep the same due date (the 2018 "MOT-style" rule). Give existing tenants a copy of the record within 28 days of the check, and new tenants before they move in.
Jump to: Calculator · The rules · Worked examples · Several appliances · Check vs service · Tenant won't let you in · For gas engineers · FAQ
Gas safety check date calculator
Type the date on the current gas safety record. Everything stays in your browser. Nothing you type is sent anywhere.
How the dates are read: the due date is the same date 12 months after the check (a check on 29 February is due on 28 February). The early window is the 2 months ending with the due date, so for a 15 March due date it opens on 16 January. HSE's leaflet describes it as "10 to 12 calendar months after the previous check". If your engineer prints a different expiry date, go by the earlier of the two.
The rules, in one table
| Rule | What it means | Where it's from |
|---|---|---|
| Annual check | Every gas appliance and flue you provide is checked within 12 months of being installed, then at intervals of not more than 12 months. | Reg 36(3)(a) |
| Early window keeps the date | A check in the 2 months ending with the due date counts as done on the due date, so you don't lose any months. | Reg 36A(1) |
| Lining appliances up | Once per appliance, you can check it up to 2 months after its due date, but only to bring its date into line with another appliance in the same home. | Reg 36A(2) and (3) |
| New tenancy | Before a new tenancy starts, each appliance must have been checked in the 12 months before the start date (or within 12 months of installation, if later). | Reg 36(3)(b) |
| Copy to tenants | Existing tenants: within 28 days of the check. New tenants: before they move in. Lets of 28 days or less: you can display it prominently instead. | Reg 36(6) |
| Keep the record | Until there have been two further checks (so usually about 2 years, longer if checks were early). For an appliance that's removed, 2 years from its last check. | Reg 36(3)(c) |
| What the record shows | Date, address, landlord's (or agent's) name and address, each appliance or flue and where it is, any defect and what was done, the engineer's name, signature and Gas Safe number. | Reg 36(3)(c) |
| Who does it | A Gas Safe registered engineer, qualified for that kind of appliance (it's on the back of their ID card). | Reg 36(4), HSE FAQ |
| Can't be passed to the tenant | A tenancy clause can't make the tenant responsible for the check. Tenants' own appliances aren't covered, but the pipework to them is. | Reg 36(10), HSE FAQ |
Sources: regulation 36 and regulation 36A on legislation.gov.uk, HSE's landlord guide INDG285 and its landlord FAQ, all read 29 October 2026. Northern Ireland has its own regulations (2004) with a similar annual check: check nidirect there.
Worked examples
Each of these was run through the calculator above.
| Situation | Next check due | Why |
|---|---|---|
| Last check 15 March 2026 | 15 March 2027; book any time from 16 January 2027 | 12 months from the check. |
| Due 15 March 2027, done early on 1 February 2027 | 15 March 2028 | Within the 2-month window, so it counts as done on 15 March 2027. Tenants still need their copy by 1 March 2027 (28 days from the real visit). |
| Due 15 March 2027, done on 10 January 2027 | 10 January 2028 | More than 2 months early: the 12 months restart from the visit, and 2 months are lost. |
| Due 15 March 2027, done late on 1 April 2027 | 1 April 2028 | The check was late (unless it was the one-off alignment move). The new 12 months run from the visit. |
| Last check 15 March 2026, new tenant moving in 1 April 2027 | A new check before 1 April 2027 | The tenancy starts after 15 March 2027, so the old check isn't in the 12 months before it. |
| Last check 29 February 2028 | 28 February 2029 | There's no 29 February in 2029, so the month's last day. |
Boiler and fire on different dates?
If a boiler was checked in March and a gas fire was added in October, you'd have two due dates in the same home and two visits a year. Regulation 36A gives you two ways to line them up:
- Bring one forward: have the later appliance checked early, with the earlier one. You lose the months it was early, once, and from then on both share a date.
- Push one back, once: for each appliance, one time only, you can check it up to 2 months after its due date, to align it with another appliance in the same property. Note this on the record or in your file, so it's clear it was alignment and not a missed check.
Most engineers check every appliance at the same visit, which keeps everything on one date from the start.
Gas safety check vs boiler service
| Gas safety check (CP12 / landlord gas safety record) | Boiler service | |
|---|---|---|
| Who needs it | Landlords, by law, for every gas appliance and flue they provide | Anyone with a boiler. Manufacturers usually ask for a yearly service to keep the warranty |
| What it is | Checks the safety matters the regulations list (including flue, ventilation, gas rate or pressure, safe operation) and produces a record | Maintenance to the manufacturer's instructions: cleaning, parts, adjustment |
| How often | At least every 12 months | As the manufacturer says. HSE suggests yearly if there are no instructions |
| Paperwork | The record, kept by the landlord, copied to tenants | A service record or benchbook entry, for the warranty |
HSE's own words: "You should not assume that an annual service inspection meets the safety check requirement, or that a safety check will, on its own, be sufficient to provide effective maintenance." Landlords still have a separate duty to keep everything maintained in a safe condition.
When the tenant won't let the engineer in
You must not force entry. What the law asks is that you take all reasonable steps, and HSE says its inspectors look for at least three attempts. Its recommended steps:
- After a missed visit, leave a note saying the engineer called, why, and how to rearrange.
- Write explaining that the check is a legal requirement and is for the tenant's own safety.
- Offer the tenant the chance to choose their own appointment time.
- Keep everything: copies of letters, texts, call notes, the engineer's "no access" card. HSE strongly advises a record of all correspondence.
The calculator writes all three letters (pick them in the "Message" list). Start early in the window, so there's time for three attempts before the due date. If it's still impossible, get advice on what the tenancy allows; it's ultimately for a court to decide whether you did enough.
For gas engineers: reminders that fill your diary
Landlord checks repeat every year on a known date, and the 2-month window means customers can book early without losing anything. That makes them easy to plan around the busy heating season. A simple routine:
- Before you leave the job, tell the landlord the next due date and that you'll remind them.
- About 10 weeks before the due date, send the email reminder (in the calculator). It says they can book from the window date without losing months.
- When the window opens, send the text version if they haven't booked.
- 4 weeks before, a final nudge. The calculator's .ics file puts all three dates in your calendar.
- On the day, send the record straight away, so the landlord can give the tenant their copy within 28 days.
For homeowners, the same routine works for the annual boiler service: the calculator has an email and a text that fits in one SMS. Only send reminders to customers who've agreed to hear from you, and include a way to opt out (for example "reply STOP and I won't remind you again").
What if the check is late?
Book it straight away. The new 12 months run from the day it's done. Missing it is a breach of the regulations, which HSE enforces: its landlord guide says you risk prosecution and "imprisonment or a fine ... or both, for each offence", with an unlimited fine in the Crown Court. An overdue check doesn't mean an appliance is unsafe, but if an engineer finds an appliance dangerous and disconnects it, it must not be used again until it's been fixed.
Gas is one of several safety duties for landlords. Electrical safety checks, smoke and carbon monoxide alarms and (in England) the new Renters' Rights rules have their own requirements: see gov.uk for each.
Gas engineer or heating firm? Our free Trades Skills make ChatGPT, Gemini or Claude write your quotes, chase unpaid invoices and reply to reviews like an experienced pro: tell quote-builder "boiler swap, combi to combi, 3-bed semi" and it writes a clear quote with scope, exclusions and payment terms. Set-up takes about 3 minutes, no coding.
Get the free skills See Trades Skills Pro
Landlord? The UK landlord records spreadsheet (£14) keeps rent and costs per property, ready for Making Tax Digital. Free tools: do you need MTD? and the Section 13 rent increase date calculator.
FAQ
How long is a landlord gas safety certificate valid for?
The law doesn't give the record an expiry date as such: it requires each appliance and flue to be checked at intervals of not more than 12 months. So the next check is due 12 months after the last one, which is the date most engineers print as the renewal date.
Can I renew a gas safety certificate early without losing months?
Yes, in the 2 months ending with the due date (regulation 36A, since 6 April 2018). Due 15 March? A check any time from 16 January keeps the next due date at 15 March the following year. Earlier than that, the 12 months restart from the visit.
When do tenants have to get a copy?
Existing tenants within 28 days of the check, new tenants before they move in. For lets of 28 days or less you can display it prominently instead. A digital copy is common; keep proof you sent it.
What happens if a landlord's gas safety certificate expires?
It's a breach of the Gas Safety (Installation and Use) Regulations 1998, which HSE can prosecute (fines, imprisonment or both, per offence). Book a check straight away: the next due date then runs from the day it's done.
Is a boiler service the same as a gas safety check?
No. The check produces the legal record; a service is maintenance to the manufacturer's instructions. Many engineers do both in one visit, but one doesn't replace the other.
What if the tenant won't let the engineer in?
Never force entry. Leave a note after a missed visit, write to explain it's a legal safety check, offer them the chance to pick a time, and keep a record of every attempt. HSE looks for at least three.
Does a tenant's own gas cooker need checking?
Not the appliance itself if it's theirs, but the landlord is still responsible for the pipework. HSE suggests reminding tenants to have their own appliances checked, and offering to include them at the same visit.
Does this apply to holiday lets, lodgers and HMOs?
Yes to holiday lets, HMOs, bedsits and B&Bs: HSE lists them all. A lodger in your own home counts if you let to them under a licence. Leases of 7 years or more aren't covered by the landlord duty.
This page is general information written by an AI agent and checked against legislation.gov.uk (SI 1998/2451, regulations 36 and 36A as amended by SI 2018/139) and HSE guidance (29 October 2026). It is not legal advice. Rules change: check the current position, and get advice for your own situation. If you spot an error, please open an issue.