G98 notification for a home battery: how to notify your DNO

The short version: what you actually have to do

Four steps cover most UK home battery jobs. Work out which route your equipment and site fall under. Find out who your network operator is. Send the right form with the type-test certificate and a schematic, either yourself or through your installer. Keep the acknowledgement or approval where you can find it later.

Two dates matter and they do not agree. Network operators publish a 28 day notification window after commissioning. The regulation behind parallel operation says the distributor must be advised before, or at the time of, commissioning. Notify as early as your installer will allow, and treat the 28 days as the outer limit rather than the target.[29][31]

G98 or G99: which route applies

G98 is an Engineering Recommendation used for connecting fully type-tested micro-generators in parallel with a public distribution network, and the current ENA catalogue describes it as applying up to and including 16 A per phase.[15] Sixteen amps per phase is commonly expressed as about 3.68 kW per phase on a nominal 230 V supply.[29]

The regulation behind that route sets three conditions: the source does not produce more than 16 A per phase at low voltage, it disconnects itself from the parallel connection when the distributor disconnects your supply, and the distributor is advised of the intention to use it in parallel before or at commissioning. Meet those and the specific-requirements negotiation in regulation 22(1)(d) does not apply.[31]

G99 covers everything else: connection above the G98 limits, more than one generator at a property, equipment without the right type-test evidence, or site circumstances that fall outside the simple route. SSEN, for example, lists a second installation by the same installer within the last 28 days as a case needing prior approval.[29] G99 is an application, so it happens before you connect, and it is the slow path.[17]

The number that decides the route is the inverter's output at the point of connection, not the battery's kWh. A 2 kWh and a 10 kWh battery can sit on opposite sides of the line depending on the inverter and the site.

Step one: find your network operator

Enter your postcode in the Energy Networks Association lookup to see which electricity distribution network operator covers the property.[32] Great Britain has several, and each publishes its own forms, portals and wording, which is why advice written for one operator can mislead you on another.

Your installer will usually know the operator already, and SSEN says an installer can notify it on your behalf by email attached to the commissioning form. If you are doing the paperwork yourself, start from the operator's own page rather than a template you found elsewhere.[29]

Step two: what the form actually needs

SSEN says a G98 submission needs property details, the proposed total generation capacity and an inverter type-test certificate whose power rating matches the inverter rating on the schematic diagram.[29] Expect the form to ask for the installation address, the commissioning date, the inverter make and model with its certificate reference, the registered capacity and any export limit, the single-line schematic, and the installer's details.

Ask for copies of everything as it goes out: the final schematic, the type-test certificate, the commissioning record, the completed notification form and any DNO response. That bundle is what you hand over if you sell the house, and it is what an installer or insurer will ask for. ENA Connect Direct is the network industry's device and application platform and a place to check generation-device information.[30]

Step three: how each operator runs it

SSEN's published route is three steps: install equipment that complies with G98 using certified inverters, submit G98 Form B within 28 days of commissioning, then wait for its review confirming the connection meets G98 requirements or asking for further action.[29] Its document library names G98 Form B as the commissioning form and G99 as application forms A1-1 and A1-2.[20]

National Grid Electricity Distribution describes its own G98 route as an online form that takes around 10 to 15 minutes and returns an instant acknowledgement, and it also says to do it within 28 days of commissioning.[33]

So the practical answer to 'how long does this take' is: the notification itself can be an afternoon's admin, while the G99 application path can take much longer and happens before connection. The operative deadline in both cases starts at commissioning.

Timelines: 28 days, and the legal wording that says earlier

The regulation is explicit: the distributor must be advised of the intention to use the source of energy in parallel with the network before, or at the time of, commissioning.[31] Operator guidance quoted above frames the same duty as a notification inside 28 days.[29][33] We are recording both readings rather than picking one, because which wording your operator enforces is a question for your operator.

What is not in doubt is that notification is a requirement, not an optional extra. It exists so the network operator knows what generation sits on its network, which is what its voltage and planning work depends on.

What happens if you do not notify

If you never notify, the operator holds no record of your generation. SSEN's review step, which confirms whether the connection meets G98 or needs further action, never happens, so nobody has confirmed your installation is inside the simple route.[29]

We have looked for a published fixed penalty for a missed household notification and have not found one, so we will not invent a figure. Treat the consequence as this: you are outside the process your operator publishes and the requirement in the regulations is unmet, and the paperwork you would need to prove otherwise does not exist.[31]

In practice, missing documentation is what bites first. Buyers, installers, insurers and the operator's own records all treat the notification or approval as the proof that your battery was connected properly.

What differs between network operators

Network operators publish different routes for the same obligation. SSEN runs the Form B notification, accepts it by email from the installer, and then reviews it.[29][20] National Grid Electricity Distribution runs an online form with an instant acknowledgement.[33] Others publish their own portals, and some expect the installer to submit everything.

Two practical consequences. First, search for your operator by name plus G98 to reach the current page rather than following a generic walkthrough. Second, if an online form says 'application', it is often just the operator's name for the notification form, but never assume that: check whether the route ends in a notification or in prior approval, because only one of those lets you connect first.[29][32]

Where a plug-in battery fits, and where it does not

A product page may say plug in while the UK installation still requires a dedicated circuit, a qualified electrician or a particular DNO process. Fox ESS's MiniQube page itself says formalised plug-in battery guidance remains limited and refers to existing electrical and grid standards, including G98 where applicable.[25]

The regulation draws the same line. Its exemption for small parallel generation expects the equipment to comply with British Standard Requirements where it is part of a low voltage consumer's installation, while a plug-in microgenerator is named against the Plug-in Solar Device Interim Product Specification, which is written for plug-in solar devices.[31] A battery is not a plug-in solar device, so its route is the electrical standards route plus your operator's process, not the solar approval.

The government's 2026 plug-in solar route does not change that. The announcement and interim specification concern plug-in solar microgeneration, not blanket permission for plug-in batteries.[3][4]

A safe G98 buying process

Before you buy, ask four questions in writing. Does this equipment have a current type-test certificate, and does its rating match the inverter rating on the schematic? Does my operator's route end in a notification or in an application? Who submits it, me or the installer? What documents do I keep at the end?

If a seller says G98 approved without giving the relevant model, certificate and process, treat the statement as incomplete. The UK plug-in battery rules guide explains the wider distinction between solar approval and battery approval, and the battery without solar guide covers what a grid-charged battery can and cannot do.