Solar Panel Certification UK: MCS, DNO, Building Regs & Warranty Explained (2026)
Every certificate a UK solar installation needs — MCS, DNO notification (G98/G99), Building Regs, electrical EIC, and manufacturer warranties. What each proves and how to replace lost ones.
Quick answer: A UK solar PV installation needs five core certificates: the MCS certificate (proves installation standards, required for SEG payments), DNO notification confirmation (G98 for small systems, G99 for larger — authorises grid connection), Building Regulations sign-off (electrical Part P and structural load), the electrical installation certificate (EIC) for the solar circuit, and manufacturer warranties for panels (10-25 years) and inverter (5-10 years). Together they form your solar paperwork pack — essential for SEG income, property sale, insurance, and warranty claims.
The five certificates explained
1. MCS Certificate — the foundation
The Microgeneration Certification Scheme certificate proves your installation was completed by a certified installer to UK standards. It's the gateway document:
- Required to register for the Smart Export Guarantee (SEG)
- Required for manufacturer warranty validity
- Expected by buyers and solicitors at property sale
- Increasingly required by home insurers
Issued by your MCS-certified installer at commissioning. See our MCS certificate guide for full detail.
2. DNO Notification (G98 / G99)
The Distribution Network Operator manages the local grid. Connecting solar requires notification:
- G98 — for systems up to 16A per phase (3.68kW single-phase). "Connect and notify" — install then tell the DNO within 28 days.
- G99 — for larger systems. Requires DNO approval before connection.
Your installer submits the notification and provides confirmation. This document proves your grid connection is authorised — essential for SEG and for legal grid feed-in.
3. Building Regulations sign-off
Solar PV usually falls under permitted development (no planning permission needed), but Building Regulations still apply:
- Part P (electrical safety) — the solar electrical work must comply; usually self-certified by the MCS installer through a competent person scheme
- Part A (structural) — the roof must bear the additional load; the installer assesses this
- A Building Regulations compliance certificate is issued, often via the competent person scheme (NICEIC, NAPIT)
4. Electrical Installation Certificate (EIC)
The solar circuit is a new electrical installation requiring an EIC under BS 7671. This:
- Confirms the solar wiring, isolators, and connection to the consumer unit are safe
- Is issued by the installing electrician
- Should be kept with your other electrical records
Related: our EICR codes guide and consumer unit certificates guide.
5. Manufacturer warranties
- Panels — typically 10-25 years (product warranty) plus 25-30 years (performance warranty)
- Inverter — typically 5-10 years, extendable
- Mounting system — often 10-20 years
- Battery (if fitted) — typically 10 years
Keep all warranty documents with serial numbers — they're claimed via the manufacturer using the installation date and serial.
The complete solar paperwork pack
- ☐ MCS certificate
- ☐ DNO notification confirmation (G98 or G99)
- ☐ Building Regulations compliance certificate
- ☐ Electrical installation certificate (EIC)
- ☐ Panel manufacturer warranty + serial numbers
- ☐ Inverter manufacturer warranty + serial number
- ☐ Mounting system warranty
- ☐ Battery warranty (if applicable)
- ☐ SEG agreement with energy supplier
- ☐ Installer commissioning report
- ☐ System schematic / single-line diagram
- ☐ Photos taken at commissioning
What each certificate unlocks
| Certificate | Unlocks |
|---|---|
| MCS | SEG payments, warranty validity, sale value |
| DNO (G98/G99) | Legal grid connection, SEG eligibility |
| Building Regs | Sale conveyancing, legal compliance |
| EIC | Electrical safety evidence, insurance |
| Warranties | Free repair/replacement of faulty components |
Replacing lost certificates
- MCS — contact your installer (£25-£50 duplicate) or search the MCS database at mcscertified.com
- DNO — contact your network operator (find via Energy Networks Association postcode lookup)
- Building Regs — local authority Building Control department
- EIC — the installing electrician or their competent person scheme
- Warranties — manufacturers, using panel/inverter serial numbers (photograph these now if you can access them)
If your installer wasn't MCS-certified
Some 2010-2015 FIT-era installations were done by non-certified installers. Without MCS you lose SEG eligibility and warranty validity. The fix: an MCS-certified installer can sometimes issue a retrofit certificate after inspection (£300-£600, may require remedial work).
At property sale
Buyers' solicitors routinely request solar certificates. Missing documents:
- Reduce sale value (1-3%)
- Prevent SEG account transfer to the new owner
- Slow conveyancing as enquiries are raised
Assemble the full pack before listing. See our property logbook and house sales guide.
FAQs
Is MCS legally required to install solar?
No — you can legally install non-MCS solar. But without MCS you lose SEG income and warranty validity, and harm your property value. In practice MCS is essential.
Who submits the DNO notification?
Your MCS installer submits it as part of the installation. You should receive a copy of the confirmation.
Do I need planning permission for solar panels?
Usually no — solar PV is permitted development for most homes. Exceptions: listed buildings, conservation areas, and some flat-roof or ground-mounted systems. Always check with your local planning authority if unsure.
How long should I keep solar certificates?
For the life of the system and beyond — they transfer to the next owner at sale. MCS and DNO documents don't expire.
Related guides
- MCS certificate for solar panels
- Solar panel installation records
- Smart Export Guarantee (SEG) guide
- Consumer unit replacement certificates
Last reviewed 2026-06-08 by Jamie Dawson, Editor.
