Gas safety is no small matter. If you’ve had a poor experience with a Gas Safe registered engineer, received an invalid certificate, or suspect unsafe work, you have the right to raise a concern. But where do you start?

In this guide, we walk through how to make a complaint to the Gas Safe Register, what issues they investigate, and how to contact them directly.

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Common Issues That May Warrant a Gas Safe Complaint

The Gas Safe Register maintains standards for gas engineers across the UK. If you’ve experienced any of the following, you may be entitled to file a formal complaint:

  • Unsafe gas installation or servicing.
  • A gas safety certificate (CP12) that appears invalid or incomplete.
  • An engineer claiming to be Gas Safe registered when they’re not.
  • Missed or failed inspections without valid reason.
  • Rude, unprofessional, or unethical behaviour by the engineer.
  • A refusal to provide a Gas Safe ID card upon request.

Note: The Gas Safe Register can investigate complaints about gas work carried out by Gas Safe registered engineers, as well as concerns about individuals or businesses working illegally without being registered. For disputes about cost, delays, or customer service, contact the business directly or use Trading Standards or ADR schemes.

Step-by-Step: How to File a Gas Safe Register Complaint

Step 1: Confirm the Engineer Is Registered

Search by name or company at:
https://www.gassaferegister.co.uk

If the engineer is not listed, this could be a case of illegal gas work, which is a serious offence.

Step 2: Gather Documentation

Before submitting your complaint, collect:

  • The engineer’s name and Gas Safe registration number.
  • A copy of your gas safety certificate (CP12), if applicable.
  • Photographs of unsafe work or installations.
  • Correspondence or receipts that support your claim.

Step 3: Contact the Gas Safe Register

Option A: Online Complaint Form Visit: https://www.gassaferegister.co.uk/gas-safety/concerns-reporting-illegal-gas-work/report-gas-work-concerns/ 
Fill in the complaint form and attach supporting documents.

Option B: By Phone Call the Gas Safe Register contact number:
0800 408 5500 (Mon–Fri, 9am–5pm)

Option C: By Post Gas Safe Register, PO Box 6804, Basingstoke, RG24 4NB

Once your complaint is received, a Gas Safe investigator may inspect the work or follow up for more information.

What Happens After You Submit a Complaint?

The Gas Safe Register typically follows this process:

  1. Initial assessment of your complaint.
  2. Site visit or inspection if needed (with your permission).
  3. Formal report outlining findings.
  4. Corrective action, the engineer may be required to fix unsafe work.
  5. If serious breaches are found, the engineer may face suspension or removal from the register.

You’ll be kept informed of the investigation’s progress and outcomes.

Download: Gas Safe Complaint Checklist

To simplify the process, we’ve created a free complaint checklist that includes:

  • Information to gather.
  • Supporting evidence to collect.
  • Step-by-step filing instructions.
  • Space to record case reference numbers.

Gas safety should never be left to chance. If you’ve experienced substandard gas work or suspect a safety issue, the Gas Safe Register has the authority to investigate and enforce compliance.

Don’t ignore your concerns, reporting issues protects you and others from potential harm.

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