GUIDE · FOR UK SOLAR INSTALLERS · 13 MIN READ

PAS 2030, TrustMark and RECC: A Guide for Solar Installers

MCS scope limit for solar PV and batteries

50kW

MCS scope limit for solar PV and batteries

Minimum cover from an MCS approved financial protection product

6 years

Minimum cover from an MCS approved financial protection product

TrustMark Home Improvement Lodgement

£45+VAT

TrustMark Home Improvement Lodgement

End of the ECO4 obligation period

31 Dec 2026

End of the ECO4 obligation period

Solar installers get asked about a lot of badges. Some are requirements, some are optional, and some only apply to a kind of work you may never do. This guide sets out what each scheme is, when a solar business actually needs it, and how much of it applies to commercial rooftops.

Last updated 22 October 2026. Every rule, date and figure is taken from MCS, NICEIC, the Chartered Trading Standards Institute, HIES, TrustMark, BSI and Ofgem pages read that day; they are listed at the end. Schemes change their rules, so check with your certification body before relying on any of it.

The schemes at a glance

Start with MCS

Every other scheme here builds on MCS, so it is worth being clear on its scope. MCS's Installer Operating Requirements say it applies to low-carbon installations up to a maximum of 50kW for electrical technologies such as solar PV and battery storage, and that work is delivered through domestic contracts (with a consumer) and commercial contracts (with an organisation, such as a developer, main contractor or landlord).

MCS is also part-way through a redesign. On its redeveloped scheme, MCS lists the key changes as Consumer Code membership no longer being mandatory, a risk-based assessment model, a 30-day window to create certificates instead of 14, centralised complaints, a new Installer Agreement held directly with MCS and a dedicated account manager. MCS says certification bodies are moving installers across in phases throughout 2026 and into 2027. Our MCS certification guide covers the steps, standards and certification body fees.

Consumer codes: RECC and HIES

A consumer code sets the rules for how you deal with householders: what you say in marketing, what goes in a quote, how deposits are protected, what the contract and guarantee must contain, and how disputes are resolved. The two that solar installers use are both approved under the Chartered Trading Standards Institute's (CTSI) Approved Code Scheme.

• RECC (Renewable Energy Consumer Code). Formed in 2006, it sets the standards for selling or leasing small-scale heat and power generators, from renewable or other low-carbon sources, to domestic consumers: marketing, pre-contract information, quotations, deposits, contracts, guarantees and after-sales service. It is run by Renewable Energy Assurance Ltd, a subsidiary of the Association for Renewable Energy and Clean Technology.
• HIES (Home Insulation and Energy Systems Contractors Scheme). A consumer protection organisation covering the installation of renewable energy products, including solar PV, battery storage and EV charging. HIES says every installation registered with it is backed by deposit protection and an insurance-backed guarantee, and that it offers alternative dispute resolution. It is also a TrustMark Scheme Provider and an MCS approved financial protection product provider.

Do you still need one? NICEIC, one of the MCS certification bodies, says Consumer Code membership remains a requirement under the current MCS scheme and must be kept to retain certification. Once you have moved onto the redeveloped scheme it is no longer a scheme requirement, and you can choose whether to keep it. MCS takes on the complaints role the codes used to play. So: don't cancel a consumer code early, or your current certification is at risk.

Joining. HIES describes a five-step accreditation process: credit and background checks on the business and its directors, a documentation check (financial statements, customer-facing documents, processes and insurance), a review of your online reputation, any further requests, then a decision. Expect any code to look at the same kind of thing.

Guarantees and financial protection

This is where most of the "insurance-backed guarantee" questions come from, and it is changing.

• On the current MCS scheme. MCS says that when dealing with domestic customers you must guarantee the workmanship for at least two years, the guarantee must transfer to a new owner if the property is sold, and it must be insured so it is honoured if you stop trading. For domestic installations an insurance-backed guarantee (IBG) is required, and you declare who provided it when you create the MCS certificate. The consumer codes oblige their members to provide one.
• On the redeveloped scheme. MCS approved financial protection products replace IBGs as mandatory. The Installer Operating Requirements say that on a domestic contract you give the customer a written guarantee for the system's design and the workmanship, and an MCS approved financial protection product. MCS says these give at least six years' cover from installation, cover the customer if you go out of business, retire or refuse to fix a problem, and cap the excess at £250. MCS also says installers still on the current scheme can already buy them in place of an IBG.

Both requirements are written for domestic contracts. Our solar installer insurance guide covers the policies you hold as a business, which are a separate question.

TrustMark

TrustMark describes itself as the government endorsed quality scheme covering work a consumer chooses to have carried out in or around their home. You don't join TrustMark directly: you register through a Scheme Provider, which runs the quality scheme you are registered under and handles standards and complaints, while TrustMark oversees the Scheme Providers. TrustMark says it licenses and audits over 35 Scheme Providers with over 15,000 registered businesses. HIES is one that covers solar PV.

The reason most solar businesses look at TrustMark is government funding: MCS says that to install renewables under ECO4 you must be MCS certified and TrustMark registered. There is also a route for self-funded home jobs. TrustMark's Home Improvement Lodgement lets a registered business lodge a record of work for a self-funding customer, including solar panel installations, with no preceding assessment needed. It costs £45 + VAT per lodgement, and financial protection meeting TrustMark's requirements must still be uploaded against each one. TrustMark says it opens up green lending and other finance for those customers.

PAS 2030 and PAS 2035

Both are Publicly Available Specifications published by BSI, and both are about homes.

• PAS 2030:2023 covers the installation of energy efficiency measures in existing dwellings. Ofgem describes it as setting out how specific measures should be installed, and TrustMark as the specification energy efficiency installers must be certified to when working under government schemes such as ECO.
• PAS 2035:2023 covers the whole domestic retrofit process, from assessment and option evaluation through installation, testing, handover, monitoring and evaluation. Ofgem calls it the over-arching document in the retrofit standards framework and expects PAS 2035 projects to be managed by a Retrofit Coordinator.

BSI says PAS 2035/2030:2023 must be used for publicly funded work under government energy efficiency schemes, naming ECO4, the Social Housing Decarbonisation Fund and the Home Upgrade Grant, and that both documents are free to download. Ofgem says the 2019 versions were withdrawn on 30 March 2025, after an 18-month transition, so only the 2023 versions are now valid.

PAS 2030 certification and solar. Ofgem's ECO4 guidance says a measure referred to in PAS 2030:2023 or falling under an MCS standard should be installed by a PAS or MCS certified installer (or under the responsibility of one). Solar PV falls under MCS, so for solar the certification is MCS; PAS 2030 certification is what an installer of measures such as insulation would hold.

Solar PV under ECO4

ECO4 places an obligation on energy suppliers to deliver energy efficiency measures to homes, and Ofgem's guidance says its obligation period runs to 31 December 2026. For solar PV, version 4.0 of the delivery guidance (26 March 2026) says:

• The installer must be accredited under MCS, or an alternative certification scheme, to show appropriate skill and experience (5.208).
• The installation must follow the relevant MCS requirements and PAS 2035:2023 (5.209).
• Measures installed to PAS or MCS must be installed by, or under the responsibility of, someone registered with TrustMark for that measure, with a TrustMark certificate of lodgement. If TrustMark voids the lodgement, Ofgem refers the measure to its rejections process (4.19, 5.256).
• Each home has a solar PV capacity cap of 10kWp, including any system already there (5.215).

MCS adds that, once certified, you work with an obligated energy supplier to deliver installations. In practice ECO4 is domestic, supplier-led work with its own paperwork, which is why it rarely overlaps with a commercial solar business.

Commercial vs domestic work

Read the scope lines of each scheme and a pattern appears:

• RECC covers selling to domestic consumers.
• TrustMark covers work in and around the home.
• PAS 2030 and PAS 2035 cover dwellings.
• MCS's written guarantee and financial protection requirements sit under "guarantees and financial protections for domestic contracts", and MCS's financial protection page talks about domestic customers.
• MCS itself covers solar PV only up to 50kW, so most commercial rooftops are outside it.

So on a commercial job, where your customer is an organisation, these badges are rarely what wins or loses the work. What a business customer and its insurer look for is different: the insurers' fire safety code RC62 recommends, as a minimum, MCS certification for PV, BS EN ISO 9001:2015, SSIP membership such as CHAS or Acclaim, the right competence for DC and AC work, and appropriate insurance including professional indemnity. See our RC62 guide for the detail. If you do both kinds of work, keep the domestic schemes for the domestic side and don't lead a commercial proposal with them.

What it costs

Only some of these costs are published:

• MCS. Certification body fees vary; our MCS guide lists the published ones, and the MID guide covers the per-installation fee.
• TrustMark lodgement. £45 + VAT per Home Improvement Lodgement; TrustMark notes some funding routes have different charges.
• Consumer codes and TrustMark registration. We couldn't find current fees published for RECC, HIES or TrustMark Scheme Providers, so ask each one directly, along with what a guarantee or financial protection product costs per job.
• PAS documents. BSI says PAS 2035/2030:2023 is free to download. Certification to it is a separate cost from a certification body.

Which do you need?

1. 1Commercial rooftops only. MCS for anything 50kW or under, plus the insurance and fire safety evidence commercial clients ask for. Consumer codes, TrustMark and PAS are not the deciding factors.
2. 2Domestic solar, still on the current MCS scheme. MCS plus a consumer code (RECC or HIES), with an insurance-backed guarantee or an MCS approved financial protection product on each domestic job.
3. 3Domestic solar, moved to the redeveloped MCS scheme. MCS, with a written design and workmanship guarantee and an MCS approved financial protection product on each domestic contract. A consumer code is your choice.
4. 4Government-funded home schemes such as ECO4. MCS and TrustMark registration, work installed in line with PAS 2035:2023, and a TrustMark lodgement for every measure.

If commercial work is where you want to grow, the badges are only half of it; the other half is getting in front of business owners who are ready for a survey. Our guide on how to get commercial solar leads compares the routes, or you can buy commercial solar leads as surveys already booked with the decision-maker.

PAS 2030, TrustMark and RECC: FAQ