Three engineering recommendations decide whether your system is notified after installation, approved before it, or fitted with an export limit. Here is which one applies to you, what each involves, and how long it really takes.
In one line: G98 is fit first and tell them within 28 days. G99 is ask first and wait. G100 is the scheme that caps your export when the network cannot take all of it.
The dividing line is 16 amps per phase of registered generating capacity. At nominal voltage that works out at about 3.68 kW on a standard single-phase supply and about 11.04 kW on three phase, as set out in the Energy Networks Association's Engineering Recommendation G98.
At or below that line, your installation is a G98 job: it can be commissioned first and notified afterwards. Above that line, it is a G99 job: your distribution network operator has to approve the connection before installation begins.
Two things catch people out.
The limit applies to the inverter, not the panels. A 5 kWp array on a 3.68 kW inverter is a G98 installation. What is registered is the capacity that can be pushed onto the network.
A battery inverter counts as generation and is added to the total. This is the one that surprises people most. A house with a 3.6 kW solar inverter that adds a separate 3.6 kW battery inverter has just gone over the line, and needs a G99 application, even though each piece on its own would have been fine. Certain integrated arrangements are treated differently, which is one of the things worth checking before you buy equipment rather than after.
A note on the three-phase figure. You will see 11.6 kW quoted for three phase in some places, including on network operator websites, while the governing ENA document calculates 11.04 kW. We use the underlying 16 amps per phase as the controlling figure, treat the kW conversions as indicative, and confirm the specific position with the network operator for your site. Where a published figure and the engineering recommendation disagree, the recommendation is the standard the installation is assessed against.
For most ordinary domestic solar installations, this is the route, and there is nothing for you to do.
How it works. Your installer commissions the system, then submits the notification to your distribution network operator. For a single property this is Form B, and it must be with them no later than 28 calendar days after commissioning. There is no waiting period and no approval step, because it is a notification rather than a request.
What the form actually contains: the site details and your MPAN, which is the long number on your electricity bill; whether the supply is single or three phase; the technology and its registered capacity; the equipment's type-test reference; any storage capacity; and the installer's declaration. Where additional type-test information is needed, Form C carries it.
One exception worth knowing. A planned programme of installations across several premises in the same area is not a straightforward notify-after job. That needs Form A and the network operator's agreement before any installation starts, with a Form B for each property afterwards. This affects developers and social landlords rather than individual homeowners.
What you should end up with. A copy of the submitted notification for your records. It matters later: when you apply for export payments, when you insure the property, and when you sell the house and a solicitor asks for it.
Anything above the G98 threshold needs approval before connection, because a larger system can affect the local network in ways the operator has to assess first.
In our area, projects above the G98 ceiling and up to 50 kW go in on an initial application form, with a commissioning form submitted after installation and an additional test form where the equipment is not type-tested. Larger projects use the full standard application form, with the more detailed technical section required from 150 kW upwards.
Applicant and site details, coordinates, site and boundary plans, access and metering locations, the maximum import and export capacity you are asking for, the date you need it by, and the technical data for the equipment. Larger projects, from 5 MVA upwards, have needed a longer list since 1 June 2026, including a letter of authority, evidence of land rights or heads of terms, a single-line diagram and a programme.
Whether the local network can accept what you are proposing. The answer is often yes as asked. Sometimes it comes back with conditions, and the most common condition by far is a limit on how much you may export, which is handled through G100 and is covered below. An outright refusal is rare; a conditional offer is not.
Be wary of anyone quoting you a fixed period, including us. What is actually regulated is the time to issue a connection quotation, not the time to get you connected and generating.
What is regulated · Standard
Those come from the Energy Networks Association's distributed generation connection guide and sit under the network operators' licence conditions.
What the standards do not cover is everything after the quotation: accepting it, any network reinforcement, land rights, the operator's own construction programme and your own works. A straightforward domestic-scale G99 on an unconstrained network is often quick. A large system on a constrained rural network is not, and reinforcement is where the genuinely long timescales live.
What makes it slower. An incomplete application, equipment that is not type-tested, an export figure the local network cannot support, and any project needing physical reinforcement.
What makes it faster. Submitting something complete the first time, using type-tested equipment, and being realistic about export from the start.
The Fast Track route. Network operators run a streamlined G99 process for qualifying smaller schemes, which takes much of the waiting out for projects that would otherwise sit in the full process. Published criteria in our area include generating units with an intrinsic design capacity no greater than 32 amps per phase, an aggregate registered capacity no greater than 60 amps per phase, type-tested inverters, and compliance with one of the standard grid-interface specifications. There is a specific application route for an integrated microgeneration and storage installation, and the commissioning confirmation is still due within 28 days.
In plain terms: many home solar-plus-battery combinations that tip just over the G98 line qualify. We check eligibility as standard, because it is the difference between a short process and a long one.
G100 is the third recommendation and the least understood. It is not an alternative to G98 or G99 and it is not a way around the connection rules.
It specifies an export limitation scheme: a technical arrangement, agreed with the network operator, that holds your export below what your system could physically produce. The system generates freely, you use as much as you like on site, and the limiter prevents more than the agreed amount going out onto the grid.
Why it matters commercially. Where the local network cannot accept your full export, the choice is often between a smaller system, a long wait for reinforcement, or the full-sized system with an export limit fitted. On a site that consumes most of its own generation, which is most farms and most working commercial buildings, the export limit costs very little in practice and keeps the project viable. This is one of the more useful things a competent installer brings to a constrained site.
What it involves. The scheme has to be declared in the connection application where export is constrained, and the commissioning evidence includes a single-line diagram, fail-safe and functional checks, the settings applied and the test results.
The most common question we get on this subject, and the answer is more involved than people expect.
Adding storage is a change to your connection, not an accessory. It has to be assessed again. If the new aggregate registered capacity still sits within the G98 ceiling, it can follow the G98 notification route. If it goes above, it normally needs G99 approval before the work happens. A qualifying integrated scheme may go through Fast Track, and where the installer sets an export limit, that needs G100 evidence.
What the network operator has to look at is the actual inverter architecture and the permission that already exists for your site, which is why a battery retrofit always starts with finding out what was originally notified.
If you have inherited a system with no paperwork, which happens constantly where the original installer has gone out of business, it can be notified retrospectively. It is worth doing: the record matters for export payments, for insurance and when you sell. We sort those out regularly.
Plug-in solar became lawful in Great Britain on 27 August 2026, under new regulations and an amended G98 process. It is a genuinely new category and it is worth being precise about what it is not.
The interim product specification limits a plug-in device to 800 VA maximum apparent power, one device per household electrical installation, and no more than four panels with no more than two in series. The device must use a standard BS 1363 plug and meet the specified electrical and product standards. The householder or installer still has to notify the network operator within 28 days.
Two things follow. It does not raise the ordinary 16 amps per phase G98 ceiling for a conventionally wired system, so none of the thresholds above have changed. And plug-in batteries are expressly excluded from the regime, with no published commencement date. Anyone selling you a battery on the basis that it can simply be plugged in is ahead of the law.
Plug-in batteries are expressly excluded from the regime, with no published commencement date.
Your distribution network operator is the company that owns and runs the physical wires into your property. It is not your energy supplier, and it does not change when you switch supplier.
Across most of the North West it is Electricity North West, which covers Greater Manchester, Lancashire and Cumbria. SP Energy Networks covers Merseyside, most of Cheshire and North Wales.
You can look yours up by postcode on the Energy Networks Association's website, or just ask us and we will tell you.
All of it, as part of every installation.
That is not a boast, it is the normal standard, and it is worth saying plainly because the paperwork is the part customers least want to think about.
We work out which route applies before anything is ordered, because equipment choice can change the answer. We prepare and submit the application or notification, supply the technical data and type-test references, handle the operator's queries, design an export-limitation scheme where the network requires one, and submit the commissioning confirmation afterwards. You get copies of everything for your records.
G98 is the notification process for small generation and storage installations, generally those up to 16A per phase, which is about 3.68kW on a standard single-phase supply. It works on a fit-and-notify basis: the system is installed and commissioned first, then your distribution network operator is notified, normally within 28 days. Your installer usually handles this.
G99 applies to larger installations, above 3.68kW per phase on single phase or above about 11.04kW on three phase, and to commercial or non-type-tested equipment. The key difference is timing: G99 must be approved by your DNO before installation begins, not notified afterwards.
G98 notification is effectively immediate, since it happens after installation. G99 typically takes eight to twelve weeks, and DNOs are generally allowed up to 45 working days to respond with a formal connection offer. Complex cases needing network reinforcement can take longer.
It varies by DNO and project. We include the application work in our quotes so there is no surprise later.
You can, but it needs technical detail most people do not have to hand, including site layout plans, location plans, and inverter type-test references. In practice it is almost always handled by the installer, and we do it as standard.
Fast Track is a streamlined route some DNOs offer for smaller generation and storage installations that would otherwise need a full G99 application. Where a project qualifies it can cut the timescale considerably. We check eligibility as part of the application.
A G99 application can be declined or offered with conditions, usually where the local network cannot accept the proposed export without reinforcement. Common outcomes are an export limit rather than a flat refusal. G98 is a notification rather than a request, though the DNO can raise issues afterwards.
Your installer normally does it. If you have inherited a system with no record of notification, it can be notified retrospectively, and it is worth doing, because evidence of notification matters for export tariffs, insurance and selling the property.
Usually yes. Adding storage changes your connection and needs notifying, under G98 or G99 depending on capacity. We handle it as part of the installation.
Tell us what you have got, or what you are planning, and we will tell you which route it needs and roughly how long it takes. If you already have a system with no paperwork behind it, we can sort that out too.
MCS certified for solar PV and battery storage, certificate NIC-601172.
