The Approved Code Scheme, operated by the Chartered Trading Standards Institute (CTSI), covers sector-specific codes of practice that CTSI has independently assessed, and businesses that follow them must offer access to free dispute resolution if something goes wrong. For a householder choosing a heating installer, an Approved Code logo signals commitments above the legal minimum, but membership can be verified and it is separate from any legal registration the work itself requires.

What the scheme is

The scheme, which was previously called the Consumer Codes Approval Scheme, is operated by the CTSI, the representative body of the trading standards profession. It is made up of more than 20 member organisations called code sponsors, some of which are trade associations and others commercial organisations, and each has its own code of practice approved by CTSI. According to the scheme, more than 40,000 UK businesses follow these codes. A code is approved only if it has been independently assessed, sets clear standards for businesses, includes fair complaints procedures and provides access to free dispute resolution.

The twelve core principles

Every approved code has to meet the same core criteria, which the scheme summarises in twelve principles. They include measures against sharp practices, trained staff, protection against misleading advertising, clear written pre-contract information, respect for the sanctity of the consumer’s home, no high-pressure selling, clear terms and fair contracts in full compliance with the Consumer Rights Act 2015, flexibility on delivery and completion dates with suitable arrangements for delays, and a requirement that consumers understand their basic rights, including cancellation rights. Two of the principles bear directly on boiler and heating work, guarantees and payment protection.

Guarantees and warranties

The scheme says code members must ensure that consumers understand all the guarantees and warranties that apply, how they differ from standard consumer rights, and the cost of any additional or optional guarantees. That mirrors a point made in the guide to manufacturer’s guarantees and extended warranties: a guarantee is an addition to statutory rights, not a substitute for them. A member’s contract should therefore explain what is offered and what it costs. How guarantees are protected if an installer stops trading is discussed in the guide to insurance-backed guarantees.

Payment protection and contracts

The scheme states that code members should ensure that clients’ money, deposits or pre-payments are protected. It also says members must give clear and transparent contracts and terms and conditions with no confusing small print, hidden costs or surprises. Those commitments sit alongside the legal rules on unfair terms and on cancellation, described in the guide to paying for a boiler by card. A customer can ask a code member how its deposit protection works before paying.

Complaints and free dispute resolution

The scheme says that businesses following an approved code must offer access to free dispute resolution if something goes wrong, and that codes must include fair, prompt complaints procedures with access to low-cost, independent advice. Court action is a different route, and time limits are covered in the guide to limitation periods for a faulty boiler installation.

An example for renewable heating

The scheme’s directory groups codes by sector, and its Homes and Property category includes a renewable energy code. One example is the Home Insulation and Energy Systems (HIES) Contractors Scheme, which covers installing renewable energy products. The directory says its code was granted Approved Code status in 2015, that it has more than 350 members and that it was last audited in November 2025. That may matter to a household considering a heat pump, as discussed in the guide to heat pump or replacement gas boiler. The directory does not make membership of a particular code a requirement for any installer.

How to verify a member

The scheme says a business that follows an approved code can display the Approved Code logo, and that consumers can also use its online directory to check that a business is a genuine member. A householder should confirm the exact company name and address on the quote against the directory entry. Code membership is also separate from the legal registration that certain kinds of work require, so it should be checked alongside the points in the guide to checking a Gas Safe engineer and the guide to TrustMark registration.

FAQs

Is an Approved Code a legal requirement for installers?

No. The scheme describes its codes as setting standards that go beyond legal requirements, and membership is voluntary.

Does the logo prove a business is a member?

The scheme says the logo shows a business has committed to the standards, and it provides a directory so that consumers can check that a business is a genuine member.

What does an Approved Code say about deposits?

The scheme says members should ensure clients’ money, deposits or pre-payments are protected.

The bottom line

CTSI’s Approved Code Scheme gives householders a way to choose installers that have signed up to an independently assessed code, with clear contracts, protected deposits, explained guarantees and access to free dispute resolution. Membership should be verified in the directory and checked alongside any legal registration that the work requires. This is general information, not regulated advice on any specific installation.

Sources

This guide draws on the following primary sources, current as of 24 September 2026:

• Chartered Trading Standards Institute, “What are Approved Codes?”
• Chartered Trading Standards Institute, “Approved Code Directory”
• Chartered Trading Standards Institute, “HIES Quality Assured Contractors Scheme”

Related guides

Best Boiler Deals is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not regulated advice on any specific installation — always confirm the details with a Gas Safe registered engineer.