How to Check a Plumber on the Gas Safe Register

How do I check a plumber on the Gas Safe Register?

Go to gassaferegister.co.uk and use the check an engineer search, or telephone 0800 408 5500 and read the number out. You can search by the licence number on the card, by business name, or by postcode. The record that comes back tells you whether the registration is live, which business holds it, and the categories of gas work that engineer currently holds. Do it while they are still in the doorway, not afterwards.

The licence number search is the precise one and it is the one to use. A business name search is useful when somebody has given you a trading name over the phone but no number, though names are not unique and you can land on a similar firm in another part of the country. The postcode search is a directory rather than a verification tool. It lists registered businesses near you, which is how to find somebody, not how to confirm the somebody in front of you.

Anyone carrying out work on gas pipework, a gas boiler, a gas fire or a gas cooker in a domestic property has to be on the register. That is a legal requirement, not an industry badge, and it applies to the individual doing the work rather than to whoever answered the phone when you booked. It costs nothing and it is the one check that separates a competent visit from a gamble.

• Licence number search: the accurate check, use this one.
• Business name search: use when you have a name and no number, then confirm the address matches.
• Postcode search: a directory of registered businesses, not proof about the person at your door.
• Telephone 0800 408 5500: use when the website returns nothing and you want a human to confirm.

What the Gas Safe ID card actually shows

The front of the card carries a photograph, the name of the engineer, a unique licence number, a start date and an expiry date, the registration number of the business that holds the registration, and a security hologram. The back carries the list of gas work categories that engineer is qualified for, each one with its own expiry date printed beside it. Front proves registration. Back proves scope. They are two different questions and almost nobody asks the second one.

That second question is the useful one. Gas qualifications are granted category by category, so an engineer can be correctly and currently registered while holding nothing that covers a boiler. Somebody qualified on cookers and gas fires is properly on the register and has no business commissioning a combi. Turn the card over, find the category that matches the appliance, and check the date beside it rather than the date on the front.

The categories you will see most often in a London flat or house are the core unit that everybody holds, the unit covering boilers and water heaters, and the separate units for cookers, fires and laundry appliances. A combustion analysis unit sits alongside them for anyone taking flue gas readings. You do not need the codes memorised. You need to look at the back, find the line that relates to your appliance, and confirm it has not expired.

• CCN1, the core domestic gas safety unit almost every domestic engineer holds.
• CENWAT, central heating boilers and water heaters, the one that matters for a boiler.
• CKR1 for cookers, HTR1 for fires and space heaters, LAU1 for laundry appliances.
• CPA1, combustion performance analysis, held by anyone taking flue gas readings properly.
• MET1 and related meter units, which most domestic heating engineers do not hold and do not need.

A card that is in date on the front and blank or expired on the back for your appliance is not a licence to work on it. Check the category, not just the photograph.

What the numbers on the card mean

There are two numbers and they answer different questions. The licence number belongs to the individual engineer and follows that person. The registration number belongs to the business and is the one that appears against the company in the public record. When you search the register you can use either, and the honest habit is to use the licence number, because that is the only number tied to the specific human being standing in your hallway.

The expiry date on the front relates to the card itself and is renewed annually, so an in date card means the registration was live when the card was issued. The dates on the back relate to the underlying qualifications, which run on their own longer cycle and are re-assessed periodically rather than every year. That is exactly why the back can show a category that has run out while the front still looks perfectly current. Both matter. The one relevant to your boiler is on the back.

Why the card and the register sometimes disagree

The most common reason is that the engineer has changed employer. Registration is held by the business, not by the individual, and the card is issued against that business. Somebody who moved firms three months ago may be entirely competent and legitimate, and still be carrying a card naming a company they no longer work for while their current employer holds a different registration. The register shows the current position. The card shows the position on the day it was printed.

The other reasons are less comfortable. A registration lapses if the annual renewal is not paid, and a card in a pocket does not reverse that. An individual can be removed from a business registration while the business itself continues. A firm can cease trading under one name and continue under another, which leaves customers holding paperwork with a name that returns nothing. And occasionally the person attending is subcontracted in by a firm that holds no registration at all, which is the case the check exists for.

When the card and the register disagree, the register wins. The register is the live record and the card is a printed snapshot. If the number returns nothing or returns a business that does not match what you were told, stop and ask the question directly before any appliance is opened. A straight answer takes ten seconds.

Check the business you hired, not only the person who turned up

Book through a trading name, a comparison site or a call centre and the person who arrives frequently works for a different firm to the one you contracted with. That is legal and common. It matters because your contract, your recourse and your paperwork all sit with whoever you paid, while the gas registration sits with whoever actually did the work. If those are two different businesses and nobody told you, you want to know that before the invoice rather than after a dispute.

So check both ends. Confirm the name of the business on the card, search that name or number on the register, and compare it against the name on the quote you accepted. If they differ, ask who you are contracting with and who is liable for the work. A firm operating honestly has a clear answer, usually that the engineer is employed by the registered trading entity behind a customer facing brand name. A firm that cannot explain the relationship is worth a second thought.

This is also where paid placement bites. Any business buying clicks or paying for prominence in a directory or a map listing is carrying an acquisition cost on every job, and that cost is recovered somewhere in the price or in the volume of work sold. It says nothing about competence in either direction, and it is not a reason to distrust anyone. It is a reason to run the register check yourself rather than treating a prominent listing as verification, because prominence is purchased and registration is not.

Apply the check to us as well. Ask whoever attends for the licence number, take thirty seconds and search it. An engineer who minds is telling you something worth hearing.

Gas Safe does not cover your hot water cylinder

A Gas Safe search tells you nothing about whether somebody is competent to touch an unvented hot water cylinder, because that is not gas work. Unvented cylinders sit under a separate competency with a separate certificate, its own reference number and its own expiry date, and it is held independently of any gas qualification. Plenty of excellent gas engineers do not hold it. Plenty of unvented specialists hold it without touching gas at all.

The practical consequence in London is significant, because a large share of the hot water in the capital comes off a sealed unvented cylinder, a thermal store in a purpose built block, or an electric cylinder with no gas anywhere near it. If your problem is a weeping tundish, a relief valve that will not reseat, a flat expansion vessel or a cylinder replacement, the register check is the wrong check. Ask instead for the unvented certificate by name, look at the number and the date on it, and confirm the name matches the person attending.

Water regulations competency is a third and separate thing again, relevant where the work touches the incoming main, backflow protection or a new connection. None of the three certificates implies either of the others. The correct question is never whether an engineer is qualified in general. It is whether this engineer is qualified for this specific piece of equipment, and that is answered with a different piece of paper for each.

• Gas appliance, gas pipework, gas boiler: Gas Safe registration plus the right category on the back of the card.
• Unvented hot water cylinder: the separate unvented hot water storage certificate, checked by number and date.
• Work on the incoming main or backflow protection: water regulations competency, separate again.
• Electric immersion and cylinder controls: electrical competency, which none of the above covers.

What to ask for before anyone opens an appliance

Ask for four things and ask for them at the door. The card in your hand rather than waved from a distance, the licence number so you can search it, the business name so you can compare it against the quote, and the specific category on the back of the card that covers the appliance being worked on. For cylinder work, ask for the unvented certificate as well. The whole exchange takes a minute.

The reaction is as informative as the answer. An engineer who does this for a living hands the card over without thinking about it, because it happens constantly and because the card exists precisely so it can be handed over. Reluctance, irritation, a card that is always in the van, a photograph that does not obviously match, a laminated printout instead of a proper card with a hologram, or a number that returns nothing: none of those individually proves anything, and all of them mean you slow down and get it confirmed before any work starts.

What you should be given after the work

For a landlord gas safety check, a gas safety record listing every appliance, the readings taken, the outcome against each appliance, the date, and the name and licence number of the engineer who attended. For a new gas boiler, the installation has to be notified and the notification certificate arrives afterwards, along with the manufacturer commissioning section filled in properly with actual figures in it rather than ticks. For unvented cylinder work, a record written against that cylinder with the readings on it.

The licence number on that paperwork is the second half of the check and hardly anyone uses it. Search the number on the record you were handed. It should return the same engineer and the same business you dealt with. Paperwork issued under a number that does not resolve, or that resolves to somebody who was never in your property, is a genuine problem and one you want to find before you rely on that document at a tenancy renewal or a sale.

What to do if the person at your door is not registered

Stop the work before any appliance is opened, do not let unregistered gas work continue on the strength of an explanation, and get anything already done inspected by a registered engineer before the appliance is used. Gas Safe operates a reporting route for unregistered gas work and investigates what it receives. You do not need proof to make a report, only what you saw.

The realistic version of this situation is usually not a confrontation. Far more often it is a registration that lapsed at renewal, a card naming a previous employer, or a competent engineer sent by a firm that does not hold its own registration. Those are all resolvable, and asking plainly is how they get resolved. What is not acceptable is proceeding on the basis that it will probably be fine, because gas work carried out by somebody who was not registered leaves you with an appliance nobody can vouch for and paperwork that will not stand up when it is needed.

If work has already been completed by somebody you could not verify, have the appliance checked and keep the invoice. An engineer looking at the job can tell you in an hour whether the work is sound, and that answer is worth more than speculation about who was or was not on a list.

If you can smell gas, this stops being a paperwork question. Turn the supply off at the meter, open windows, avoid switches and naked flames, leave the property and ring the National Gas Emergency Service on 0800 111 999.

Where the register check sits in the rest of the hiring decision

The register answers one question completely and every other question not at all. It tells you whether a named person is signed off to work on gas today. It says nothing about what the work should cost, nothing about how the firm behaves when something goes wrong, nothing about whether anybody will come back if the repair does not hold, and nothing at all about the cylinder in your airing cupboard. Those are separate checks with separate answers, and the rest of this section says which one answers what.

Start with the badges, because they are the most quoted and the least understood. Checkatrade, Trustatrader and what a directory badge actually means sets out what a directory has genuinely verified before it issues one and what it has simply taken on trust at sign up. The companion question, are directory reviews trustworthy, deals with the moderation and the incentives sitting behind the star average rather than with the arithmetic of it.

Then the behaviour. Common plumbing scams and how to avoid them describes the mechanisms that separate people from their money, none of which require anybody to be unregistered, which is precisely why a clean register search is not the end of the homework. The list of signs of a bad plumber covers the earlier version of the same material, the things that are visible before you have agreed to anything at all.

Then the conversation itself. Our guide on how to find a good plumber walks the filtering through in the order that removes the most options for the least effort, from registration to insurance to the way a firm answers a question about price, and it is the page to read before you start ringing round rather than after.

The questions to ask a plumber before they start work are the narrower set, the ones that belong in the last minute before anybody opens an appliance or lifts a floorboard. They overlap with the register check deliberately, because the card in your hand and the scope agreed at the door are the two things people wish they had pinned down when a job turns into a dispute weeks later.

And where the appliance is a sealed cylinder rather than a gas boiler, the whole question moves. An unvented cylinder repair is not gas work, so a register search returns nothing useful about it, and what you want instead is a G3 qualified plumber whose certificate carries its own number and its own expiry date. On a great many London properties that is the only credential that was ever relevant.