MCS certification for solar and heat pumps: is it worth it for a 2-man firm?

A plumber I know spent most of last winter turning down heat pump enquiries. He can fit one. He's fitted plenty. But every caller asked the same thing within about ninety seconds: "are you MCS registered, because I want the grant." He said no, and that was the end of the conversation. By March he'd counted eleven of those calls and worked out roughly what he'd waved goodbye to.

That's the position a lot of small firms are in. The technical side is not the barrier. The certificate is.

So this is the honest version. What MCS actually costs in 2026, what it unlocks, how long it takes, and the maths on whether it stacks up for a firm of two.

What MCS actually is

The Microgeneration Certification Scheme is a product and installer standard for small-scale renewable kit. Heat pumps, solar PV, solar thermal, biomass, small wind. It covers both the hardware and the firm putting it in.

It is not a licence to work. Nothing in law stops you fitting an air source heat pump tomorrow if you're competent and you notify the electrical and water side properly. What MCS does is act as the gatekeeper for public money and for export payments. Government schemes need a way to know the install was done to a standard, and MCS is the mechanism they chose.

You do not apply to MCS directly. You apply through a certification body, and they assess you against the MCS standards. The list of bodies is on the MCS website, and includes names most trades already know from Part P and Gas Safe work: NICEIC, NAPIT, Certass, and others. They set their own fee structures, which is why the numbers people quote vary so much.

What certification actually unlocks

Three things, and they're worth being precise about because they're the whole business case.

1. Boiler Upgrade Scheme work

The Boiler Upgrade Scheme in England and Wales pays £7,500 towards an air source or ground source heat pump. From 21 July 2026 that rises to £9,000 for eligible off-gas-grid properties moving away from oil, running to 31 March 2027. Check the current figures on gov.uk before you quote, because the values have moved twice in two years.

Crucially, the grant is applied by the installer, not the homeowner. You apply on their behalf, the money comes off the price they pay, and Ofgem reimburses you. That only works if you're MCS certified. No certificate, no grant, no quote.

2. Smart Export Guarantee on solar

SEG is the payment a customer gets for the electricity their panels export back to the grid. Every SEG supplier asks for an MCS certificate for the installation before they'll set up the tariff. Fit an array without it and the customer keeps the self-consumption savings but loses the export income entirely.

Most solar customers find that out from a forum or a comparison site before they sign anything. It kills the job.

3. The customer's shortlist

This is the quiet one. The MCS installer search is where a lot of homeowners start, and being on it means you appear in front of people who have already decided to spend money. Uncertified firms are competing on cold enquiries. Certified firms are competing on a list the customer went looking for.

What it costs in 2026

Certification bodies price differently and MCS itself is upfront that the total varies. These are the ranges to budget against, and you should get written quotes from two or three bodies before committing.

• Initial application and assessment: roughly £1,000 to £2,500, depending on the body and how many technologies you're certifying for. Adding solar PV alongside heat pumps costs more than either on its own, but less than doing them as separate applications later.
• Annual certification and surveillance audit: roughly £500 to £1,500 a year. The audit is not optional and it is not a formality.
• Consumer code membership: roughly £300 to £800 a year. You have to belong to an approved consumer code, most commonly RECC or HIES, and it is a condition of holding MCS. Some codes price on install volume.
• Per-installation registration: around £30 every time you log a completed job on the MCS database. On twenty installs that's £600 a year.
• Technical qualifications: if your lads don't already hold them, budget £1,000 to £1,500 per person per technology for the Level 3 courses.

Some bodies bundle MCS with Part P competent person registration and consumer code membership into one annual figure, often somewhere in the £800 to £1,200 range. If you're already registered with one of them for electrical work, ask about the bundle before you go shopping. It's frequently the cheapest route and nobody offers it unless you ask.

Worked example: a two-man firm going for heat pumps

Take Adam Wójcik trading as Wójcik Plumbing and Heating. Two of them, domestic work, mostly boilers and bathrooms, based in the Midlands. Day rate for the business is £250 per man per day. He wants to add air source heat pumps.

Year one

• Level 3 heat pump systems course, both men: £1,200 each = £2,400
• MCS application and initial assessment, one technology: £1,400
• Consumer code membership (RECC), year one: £450
• Insurance uplift, public liability plus workmanship warranty: £300
• Four days off the tools writing the quality management documentation and sitting the assessment: 4 × £250 = £1,000
• Year one total: £5,550

Year two onwards

• Annual certification and surveillance audit: £900
• Consumer code membership: £450
• Installation registration fees, 20 installs at £30: £600
• Ongoing total: £1,950 a year

What it earns

A typical domestic air source install for a three-bed semi quotes at around £11,000 gross. With the £7,500 grant applied, the customer pays £3,500. Adam's margin after kit, labour, and the design work is around £2,200 per job.

• Job 1 margin: £2,200. Year one costs still £3,350 down.
• Job 2 margin: £2,200. Now £1,150 up.
• Job 3: comfortably clear.

So the certification pays for itself on the third install of year one. After that, at twenty installs a year, he's carrying £1,950 of annual cost against roughly £44,000 of margin. That's about 4.4% of gross margin going on being allowed to bid at all.

Run the same maths at six installs a year and it looks different. £13,200 of margin against £1,950 of fixed cost is 15%, and you've spent four days of your life on paperwork for it. That's the line. Below roughly eight to ten installs a year, MCS is an expensive hobby.

What you need in place before you apply

Certification bodies assess the business, so one qualified person can carry a firm of two. That's the good news. Here's the checklist.

Technical qualifications. For heat pumps, a recognised Level 3 heat pump systems qualification plus water regulations. Ground source adds the loop side. For solar PV, a Level 3 solar PV installation qualification, and someone electrically competent to do and notify the work. If you're not already on a Part P competent person scheme, sort that first, because it's cheaper bundled.

A quality management system. This is the part that catches everyone. You need documented procedures covering how you handle enquiries, design, quotations, installation, handover, commissioning records, complaints, and corrective action. Not a folder of good intentions. Written, dated, version-controlled, and actually followed.

Design capability. For heat pumps you're doing a room-by-room heat loss calculation to MCS standards on every job. Not a rule of thumb, not last job's spreadsheet with the numbers changed. This is where most first audits fail.

Consumer code membership. RECC or HIES. Apply for this in parallel, not after, because it's a condition of certification and the timing catches people out.

Insurance. Your public liability needs to cover the work and most codes want workmanship warranty cover on top. Check your existing policy actually extends to renewables before you assume it does. Plenty don't.

Realistically that's two to four months from starting the paperwork to holding the certificate if the qualifications are already there. Add two or three months on top if they're not.

Solar or heat pumps first?

If you can only do one, the honest answer depends on which trade you came from.

If you're a plumber or heating engineer, heat pumps. The grant is the single biggest driver of enquiries in the domestic market right now, the job value is higher, and the design skills overlap with what you already do on wet systems. The certification cost is recovered faster because each job carries more margin.

If you're an electrician, solar PV. You're most of the way there on competence, you're probably already on a competent person scheme, and the certification adds a technology to a body you're already paying. The per-job margin is thinner than heat pumps, so you need volume, but the barrier to entry from where you're standing is much lower.

Doing both at once costs more upfront but less than two separate applications a year apart. If you know you want both, do them together.

What NOT to do

1. Don't take the first certification body quote. The spread between bodies on the same scope is wide, and the bundled packages are not advertised. Ring three, ask specifically about bundling with Part P or your existing registration, and ask what the annual audit costs in year two rather than just the joining fee.
2. Don't leave the quality management documentation until the assessor books in. This is the single most common reason a first assessment gets a non-conformance. Write it properly, over a few weeks, and use it on live jobs before the audit so it reflects what you actually do.
3. Don't quote grant jobs before your certificate is in hand. The customer's grant application depends on your certification being live at the point of install. Quoting on a certificate you expect to hold in six weeks is how you end up eating £7,500.
4. Don't guess the heat loss calculation. An undersized heat pump generates a cold customer, a complaint through the consumer code, and a mark against you at the next surveillance audit. Do the room-by-room properly or subcontract the design until you're quick at it.
5. Don't assume your insurance follows you. Renewables are frequently excluded or sub-limited on a standard trade public liability policy. Get it in writing from your broker before the first install, not after the first claim.

The short answer

For a firm of two, MCS is worth it if you can genuinely see eight to ten grant-eligible jobs a year coming through the door. If your enquiries already include people asking about the grant, you're probably there and you're just turning the work away.

If you're hoping certification will create the demand rather than let you serve demand you can already see, be more careful. The certificate opens a door. It doesn't fill the diary.

Either way, the admin load goes up the day you certify. Commissioning records, handover packs, registrations logged within the deadline, an audit trail that survives someone looking at it in eighteen months. Firms that already run their job records properly barely notice. Firms running off a notepad and a phone camera feel it immediately.