Competent person schemes explained: which London trades can self-certify their work, and the certificates you must receive

A great deal of everyday building work in a London home is covered by the Building Regulations: replacing a boiler, adding an electrical circuit, fitting new windows, re-roofing. For each of these, the law offers two routes to show the work complies. You can apply to a building control body, which inspects and certifies the work. Or you can hire a tradesperson registered with a competent person scheme, who certifies their own work and notifies building control for you.

The second route is quicker and cheaper, and it is how most such work is done. It is also an obvious opportunity for the dishonest: a logo on a van costs nothing, and many homeowners never discover a certificate is missing until a buyer's solicitor asks for it. This guide explains which trades the schemes cover, how to check a registration and what paperwork you should receive. It reflects GOV.UK and legislation.gov.uk as checked on 20 October 2026.

What the schemes are, and who authorises them

According to GOV.UK, installers can join a competent person scheme to self-certify certain types of building work "instead of getting building regulations approval". The Ministry of Housing, Communities and Local Government authorises the schemes, and installers must demonstrate they meet minimum technical competence requirements for each type of work they register for.

The current list, last updated by GOV.UK on 17 September 2026, includes bodies such as APHC, BESCA, Blue Flame Certification, CERTASS, Certsure (trading as NICEIC), FENSA, HETAS, the Installation Assurance Authority, NAPIT, CompetentRoofer and OFTEC. The Gas Safe Register is listed with a note that it is not technically a competent person scheme, but in practice its installers have the same responsibilities for complying with the Building Regulations.

Which trades can self-certify which work

Registration is not general: each scheme covers specific types of work, and each installer is registered only for the work they have been assessed on. GOV.UK's tables set out the following broad categories:

• Gas appliances - Gas Safe Register.
• Oil and solid fuel appliances - including OFTEC and HETAS among others.
• Electrical installations in dwellings - including NICEIC (Certsure), NAPIT, BESCA and Blue Flame Certification.
• Heating and hot water systems - several schemes, including Gas Safe Register, APHC and NAPIT.
• Plumbing and water supply - including toilets, basins, baths, showers and bathrooms in dwellings, where no shared or underground drainage is involved.
• Replacement windows, doors and rooflights - including FENSA and CERTASS.
• Replacement roof coverings on pitched and flat roofs - NAPIT and CompetentRoofer.
• Cavity and solid wall insulation, mechanical ventilation and microgeneration - various schemes.

The scope limits matter. A window fitter registered for replacement windows in an existing house is not certifying a new opening in a structural wall; that needs building control. A heating engineer registered for gas is not automatically registered for electrical work beyond what their scheme allows. Always check that the registration covers the specific job.

Work that needs neither approval nor a scheme

Some work is exempt. GOV.UK's guidance on when you do not need approval lists examples including most repairs and like-for-like replacements (but not heating systems, oil tanks, fuse boxes or glazing units), new power and lighting points or changes to existing circuits except around baths and showers, replacing baths, toilets, basins and sinks, and fitting gutters and downpipes. GOV.UK adds that you must still meet safety and energy efficiency standards even where formal approval is not needed. For electrical work specifically, Approved Document P sets out what is notifiable.

A tradesperson who says "it doesn't need certifying" about a new consumer unit, a boiler swap or replacement windows is wrong, and that alone tells you something.

How to check a registration properly

1. Get the business's full legal name and registration number in writing, on the quote.
2. Search the scheme's own register - for example the Competent Persons Register, the electrical competent person register, the Gas Safe Register, FENSA or CERTASS. Do not rely on a certificate photograph or a link the trader sends you.
3. Check the work types listed against what you are commissioning.
4. Check the individual as well as the business where the scheme allows it. Gas Safe engineers carry a photo ID card listing the work categories they are qualified for.
5. Match the name on the register to the quote, the invoice and the bank account. If the registered business is a subcontractor, ask for that in writing too.
6. Look up limited companies on Companies House and check the registration date and directors.

The certificates you should receive - and when

Regulation 20 of the Building Regulations 2010 is explicit. Where work is carried out by a registered person, they must, not more than 30 days after completion, give the occupier a copy of the compliance certificate and give building control either notice or the certificate itself. The regulation also says the certificate is evidence, but not conclusive evidence, that the requirements have been met.

Depending on the job, your paperwork should include:

• a Building Regulations compliance certificate from the scheme;
• for electrical work, an Electrical Installation Certificate or Minor Works Certificate to BS 7671, issued by the installer;
• for gas and heating work, the commissioning record and manufacturer's warranty registration;
• for windows and doors, the scheme certificate and the product guarantee;
• any insurance-backed guarantee offered as part of the contract.

Put the 30-day deadline in your contract and hold back a final payment until the certificate arrives. It is entirely reasonable, and it is the strongest incentive you have.

Why the certificate matters when you sell

The Law Society's TA6 property information form, a standard form sellers are commonly asked to complete when selling a home in England and Wales, asks about alterations and the approvals and certificates that go with them, including electrical installation work. A missing certificate can lead to delay, renegotiation or a request for retrospective checks just when you least want them.

If you discover that work was never certified, GOV.UK explains that you can apply to your local authority for regularisation - retrospective approval for work carried out after 11 November 1985. You may need to make alterations before the authority will agree the work complies. Contact the scheme operator first: if the installer was registered at the time, the scheme may be able to trace or reissue the notification.

Red flags

• a scheme logo but no registration number, or a number that does not appear on the register;
• a registration in a different business name from the quote or invoice;
• "we don't need to tell building control" about a boiler, fuse board, new circuit or windows;
• a request to pay cash for a "discount" in return for skipping the paperwork;
• certificates promised "later" with no date, especially once final payment has been made;
• a general builder who says their "mate" is registered but will not name him.

When building control is the better route

Competent person schemes are designed for discrete jobs. For structural alterations, extensions, loft conversions or anything combining several types of work, apply to your borough's building control service or a registered building control approver, as GOV.UK describes. Individual trades on the project may still self-certify their parts, but an inspector will see the whole job - and that independent pair of eyes is worth having on any work you cannot easily inspect yourself.

Sources (checked 20 October 2026): GOV.UK, Competent person schemes; GOV.UK, When you do not need approval; GOV.UK, Building regulations approval: how to apply; Building Regulations 2010, regulation 20; Approved Document P; Law Society, TA6 explanatory notes; Competent Persons Register; Gas Safe Register. Nothing here is legal advice.