Solar PV commissioning certificates: what the record has to show
A solar PV commissioning record confirms a grid-connected PV system was designed, installed, inspected and tested before handover, against BS 7671 Section 712, the IET Code of Practice and BS EN 62446-1. The connection itself is notified to the network operator under G98 or G99, depending on capacity per phase.
Last updated 15 October 2026. Written by the CertSync team and checked against the standards.
The short answer
A grid-connected solar PV commissioning record confirms that a PV installation was designed, installed, inspected and tested before being handed over. Three documents sit behind it: BS 7671 §712, which covers PV supply systems as part of the wiring regulations; the IET Code of Practice for Grid-Connected Solar PV, which covers the design and installation practice; and BS EN 62446-1, which sets out the documentation, commissioning tests and inspection content for the system. Separately from all three, the connection itself is notified to the network operator under ENA EREC G98 or G99 depending on capacity per phase.
Three documents, three different jobs
BS 7671 §712 is the part of the wiring regulations that deals with PV supply systems — the DC side, the isolation arrangements and how the array interacts with the rest of the installation. The IET Code of Practice for Grid-Connected Solar PV covers design and installation practice around that. BS EN 62446-1 is the one that shapes the paperwork: it sets out what the system documentation and the commissioning test report should contain.
That division explains why a PV job produces a fuller pack than a single certificate. The electrical work is certified to BS 7671 in the usual way, and the commissioning record carries the system-specific detail — array and string configuration, the inspection results and the measured test values — that a general certificate has no fields for.
Strings, inverters and the multi-inverter trap
Domestic reference material tends to assume one inverter, which is fine until it is not. Commercial and industrial arrays commonly run several inverters, and BS EN 62446-1 expects the documentation to make clear which strings feed which inverter — without that linkage, a later fault on one string cannot be traced back through the record to the equipment it was connected to.
The practical consequence is that a commissioning record should treat inverters as a collection rather than a single set of fields, with each string referenced to the inverter it feeds. The same applies to the test results: per-string readings are only meaningful if the record says where the string went.
G98 or G99 — a capacity question, not a building question
Connecting generation to the distribution network is governed by the Energy Networks Association engineering recommendations. In outline, G98 covers smaller installations that can be connected and then notified, using factory-set protection settings; G99 covers larger ones, which need an application before connection and protection settings agreed with the network operator for that specific project.
The boundary between them is a capacity threshold stated per phase, which is why the split is not a proxy for building type. A modest three-phase commercial system can sit on the G98 side, and a large single-phase domestic system can sit on the G99 side. Check the current criterion against the installation rather than assuming domestic means G98.
MCS registration — a scheme route, not a legal minimum
MCS is a certification scheme for small-scale renewable installations, with its own installation standard for solar PV. It is not a legal requirement to install a PV system, but it is normally the practical route to consumer-facing schemes: export arrangements and grant or incentive programmes generally expect an MCS-registered installer and an MCS certificate for the installation.
That makes MCS a separate output from the commissioning record rather than a replacement for it. The commissioning record evidences that the system was tested and works; the scheme certificate evidences that a registered installer did it under an audited scheme.
Frequently asked questions
- What standards does a solar PV commissioning record sit under?
- BS 7671 §712 for PV supply systems as part of the wiring regulations, the IET Code of Practice for Grid-Connected Solar PV for design and installation practice, and BS EN 62446-1 for the documentation and commissioning test content. The network connection is handled separately under ENA EREC G98 or G99.
- Is G98 for domestic and G99 for commercial?
- No — the split is a capacity threshold stated per phase, not a building classification. A small three-phase commercial system can fall under G98, and a large domestic system can fall under G99. Check the current criterion against the installation.
- Do I still need an EIC for a solar PV installation?
- The electrical installation work is certified to BS 7671 in the usual way. The commissioning record is additional to that, carrying the system-specific inspection and test content a general certificate has no fields for.
- How should a multi-inverter array be recorded?
- As a collection of inverters, with each string referenced to the inverter it feeds. BS EN 62446-1 expects the documentation to make that linkage clear, and without it a per-string test result cannot be traced back to the equipment it belongs to.
- Does a battery installed with solar PV go on the same certificate?
- No. Battery energy storage follows a different set of standards and is recorded separately, even when the two systems are installed on the same job on the same day.
- Is MCS registration a legal requirement for solar PV?
- No. MCS is a certification scheme rather than law, but it is normally the practical route into export arrangements and grant or incentive programmes, which generally expect an MCS-registered installer and an MCS certificate.
Disclaimer
This guide is general information, not professional advice, and does not replace professional judgement, training, scheme-body guidance, the network operator’s current connection criteria or the current editions of BS 7671, the IET Code of Practice for Grid-Connected Solar PV and BS EN 62446-1. CertSync does not verify the qualifications of the people using it. The contractor named on a certificate is responsible for what it certifies.
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