MCS Certificate for Solar Panels: UK Homeowner's Guide (2026)

Quick answer: The MCS (Microgeneration Certification Scheme) certificate proves your UK solar installation was completed by a certified installer to MCS standards. You need it for: Smart Export Guarantee (SEG) registration, manufacturer warranty claims, property sale evidence, and increasingly for insurance. Issued at installation by an MCS-certified installer; doesn't expire. If lost, your installer can usually supply a duplicate.

What MCS is

The Microgeneration Certification Scheme (MCS) is the UK quality assurance scheme for low-carbon energy installations. It covers:

• Solar PV (photovoltaic) panels
• Solar thermal (hot water)
• Heat pumps (air source, ground source)
• Biomass boilers
• Small wind turbines
• Small hydro
• Battery storage

Only MCS-certified installers can issue MCS certificates. The certificate is your evidence that the installation meets recognised UK standards.

What's on the MCS certificate

• Your name and installation address
• Installer's MCS-certified business name and reference
• Date of installation completion
• System type (solar PV, etc.) and component details
• System rating (kWp for solar PV)
• Each panel and inverter manufacturer, model, serial numbers
• Mounting type (in-roof, on-roof, ground-mounted)
• Inverter location and configuration
• DNO notification reference (G98/G99)
• Expected annual generation estimate

Why you need the MCS certificate

1. Smart Export Guarantee (SEG) — payment for surplus electricity

You can register for SEG with your energy supplier and get paid for surplus electricity exported to the grid. Without an MCS certificate, no SEG registration is possible. Rates vary by supplier (typically 3-15p per kWh exported).

2. Manufacturer warranties

Most solar panel and inverter warranties (10-25 years on panels, 5-10 on inverters) require evidence the installation was MCS-certified. Without it, warranty claims are difficult or refused.

3. Property sale and conveyancing

Solicitors and buyers' surveyors typically ask for the MCS certificate at sale. Without it:

• Reduced sale value (typically 1-3%)
• SEG account can't transfer to new owner
• Slower conveyancing as buyers' solicitors raise enquiries

4. Insurance

Some home insurers now require MCS evidence for solar coverage. Increasingly important from 2024-2026 as rooftop fires have made insurers cautious.

5. Building Regulations

The MCS certificate often serves as evidence of compliance with Building Regulations Part L (energy efficiency) and Part P (electrical safety, where applicable).

What documents go with the MCS certificate

A complete solar paperwork pack should include:

• The MCS certificate itself
• DNO notification confirmation (G98 for systems ≤16A per phase; G99 for larger)
• Manufacturer warranties (panels, inverter, mounting)
• Electrical installation certificate (EIC) covering the solar circuit
• Building notice or full plans approval (where required)
• SEG agreement with energy supplier (post-installation)
• Installer commissioning report
• System schematic and connection diagram

If you've lost your MCS certificate

1. Contact the original installer. They keep records and can usually supply a duplicate. Charges range £25-£50. Allow 1-2 weeks.
2. Check the MCS database. mcscertified.com — search by installer business name and date. They sometimes hold central records.
3. If the installer is no longer trading. Contact MCS directly. They may have archived records.
4. Last resort. Have a fresh MCS-certified inspector visit and issue a new certificate. Costs £300-£500 depending on system size.

What if the original installer wasn't MCS-certified?

This is a real problem. Some installations between 2010-2015 (during the FIT scheme boom) were done by non-certified installers. Implications:

• No SEG eligibility
• No manufacturer warranty validity
• Property value at sale impaired
• Insurance complications

The fix: an MCS-certified installer can sometimes issue a 'retrofit' certificate after inspection. Cost £300-£600 and may require minor remedial work.

What changes when you modify the system

If you:

• Add panels — needs a new or updated MCS certificate for the addition
• Replace the inverter — update with new MCS certificate or installer's confirmation
• Add battery storage — separate MCS certificate for the battery (Battery Storage Certification scheme)
• Move the system to a new property — the certificate doesn't transfer; new installation requires new MCS

Solar paperwork checklist (UK homeowner)

• ☐ MCS certificate (current, with installer details)
• ☐ DNO notification confirmation (G98 or G99)
• ☐ Manufacturer warranties — panels (10-25 years), inverter (5-10 years)
• ☐ Electrical installation certificate (EIC)
• ☐ Building notice / Building Regs sign-off
• ☐ SEG agreement with energy supplier
• ☐ Commissioning report from installer
• ☐ Annual performance log (optional but helpful)
• ☐ Photos of installation taken on day of commissioning

FAQs

How much does an MCS certificate cost?

The certificate itself is free — it's issued by the installer at the end of the job. The MCS-certified installation costs more than a non-certified one (typically 10-15% premium) — that's where MCS pricing flows.

Is MCS required for off-grid systems?

For pure off-grid (no grid connection), no — MCS is for grid-connected systems for SEG. Off-grid still benefits from quality assurance though.

How long does an MCS-certified installer take to deliver the certificate?

Usually within 14 days of installation completion. Some deliver on the day; some take longer if commissioning is staged.

Where can I check if my installer is MCS-certified?

mcscertified.com — search by business name or postcode. Always verify before contracting.

Related guides

• Solar panel installation records: UK homeowner's guide
• EICR for UK landlords
• Consumer unit replacement certificates
• Property logbook and house sales

Last reviewed 2026-05-19 by Jamie Dawson, Editor.