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New boiler or gas appliance: the paperwork you should have

A gas boiler installation should leave you with two pieces of paper: the building regulations certificate that arrives by post, and the commissioning checklist that keeps the warranty alive.

England rules, checked against the official sources on 2026-07-17. Wales, Scotland and Northern Ireland run their own building control regimes.

Building regulations compliance certificate (Gas Safe)

Who gives it to you: The Gas Safe registered business must notify the installation within 30 days; Gas Safe Register then posts the certificate on behalf of the council, typically within 10 to 15 working days.

What it proves: The boiler or appliance installation was notified and complies with building regulations.

Check it or get a copy: Order a duplicate from Gas Safe Register for £7.92 including VAT. Installations notified before 2009 went through CORGI, which charges more for duplicates. Official page (opens in new tab) · Check a registration number · About this scheme

Benchmark commissioning checklist

Who gives it to you: The installer completes it at commissioning. It lives in the back of the boiler manual and stays with the boiler.

What it proves: The boiler was commissioned properly. Manufacturers rely on it for the warranty, and the boiler usually has to be registered with the manufacturer within a month of installation.

Check it or get a copy: Check the back pages of the boiler manual. If it was never filled in, ask the installing business to complete it; a service engineer can complete parts of it at the first annual service. Official page (opens in new tab)

Worth knowing

  • The rules on unauthorised building work changed in 2023 and many guides are still wrong about it. A council can now serve a section 36 notice requiring work to be pulled apart or fixed for 10 years after completion (it used to be 12 months), and prosecution for breaching building regulations carries an unlimited fine and up to 2 years with no time limit. Missing paperwork does not quietly expire. Building Act 1984, sections 35 and 36, as amended by the Building Safety Act 2022 (opens in new tab)
  • When you sell, the Law Society TA6 property information form asks you to disclose alterations and attach the paperwork: planning permissions, building regulations approvals, completion certificates and scheme certificates such as FENSA. The TA6 6th edition becomes mandatory for accredited firms on 30 March 2026. Law Society: TA6 6th edition (opens in new tab)
  • Indemnity insurance is a product solicitors sometimes discuss for missing certificates (roughly £20 to £300). Whether it applies is a question for your solicitor: it does not make the work compliant or safe, and because contacting the council about the work can affect eligibility, talk to your solicitor before making any calls. HomeOwners Alliance: no building regulations approval (opens in new tab)
  • Planning permission and building regulations are separate systems. A Lawful Development Certificate covers planning only and does not remove the need to comply with building regulations, and a building regulations certificate is not planning permission. GOV.UK: lawful development certificates (opens in new tab)

If the work still needs doing, or redoing

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Common questions

What paperwork should I have for a new boiler or gas appliance?

Building regulations compliance certificate (Gas Safe); Benchmark commissioning checklist. A gas boiler installation should leave you with two pieces of paper: the building regulations certificate that arrives by post, and the commissioning checklist that keeps the warranty alive.

What if the building regulations compliance certificate (gas safe) is missing?

Order the duplicate first: it is the cheapest fix on this page and covers most cases. Source: Gas Safe Register: building regulations certificates.

What if the benchmark commissioning checklist is missing?

An unfilled Benchmark section can put the manufacturer warranty at risk. Ask the installer to complete it, and keep the first service record with the manual. Source: HHIC: the Benchmark scheme.

Does missing paperwork stop me selling the house?

Not by itself, but the TA6 property information form asks sellers to disclose alterations and attach the paperwork, and buyers' solicitors chase gaps. Reordering a lost certificate is usually cheap and fast; where work was never signed off, regularisation and other options exist to discuss with your solicitor.

This is guidance from the public rules, not legal or conveyancing advice. Your council, the scheme body and your solicitor have the final say on your situation.

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