The G98 application is the notify-and-connect route that lets you energise a small solar or battery system and tell the Distribution Network Operator afterwards, and it now sits behind a record share of UK jobs, with MCS certifying 257,397 solar installations in 2025, up 32% on the year before (MCS, 2025). If your system sits at or below 16A per phase, about 3.68kW on a single-phase supply, G98 is almost certainly the paperwork in front of you.
Getting it wrong is a compliance problem, not a filing nuisance. The current version, Engineering Recommendation G98 Issue 2, took effect on 10 March 2025 (ENA, 2025), and the submission route has moved onto the ENA Connect Direct platform. This guide follows the process an installer actually works through: who qualifies, what evidence you gather, how you notify, and the point where a job crosses into G99.
Key Takeaways
- G98 covers fully type-tested micro-generators up to 16A per phase, roughly 3.68kW single-phase and about 11kW across three phases.
- It is notify-only. You install and commission first, then notify the DNO within 28 days, with no prior approval required.
- Every generator and battery inverter must appear on the ENA Type Test Verification Report Register, quoted by its Product ID.
- Battery and hybrid inverters count toward the 16A per-phase total, so a solar-plus-storage job can tip into G99.
- Connect Direct is the 2026 digital submission route, replacing the old paper and email process.
What is a G98 application?
A G98 application is the DNO notification for a fully type-tested micro-generator connecting in parallel with the low-voltage network, up to and including 16A per phase (National Grid, 2026). Unlike G99, it needs no approval before energising. You commission the system, then notify the network within 28 days.
The full title of the standard is telling: Requirements for the connection of Fully Type Tested Micro-generators up to and including 16A per phase in parallel with public Low Voltage Distribution Networks. Two phrases carry the weight. Type tested means the equipment is pre-certified, so the DNO does not assess it case by case. Micro-generator now includes battery storage, which changes more jobs than installers expect.
Issue 2 tightened how storage and multiple micro-generators at one site are assessed, and it aligned the paperwork with the move to digital notification. If you learned the process under the older Issue 1 amendments, the core thresholds are unchanged, but the evidence and submission steps have been modernised.
Does my installation qualify for G98?
Your job qualifies when total generation stays at or below 16A per phase and every unit is type tested. On a single-phase supply that is about 3.68kW. On three phases the ceiling is three times 16A, roughly 11kW in total (1app.energy, 2026). Cross any of those limits and you move to G99.
The per-phase point matters on larger domestic and light commercial sites. A three-phase supply gives you more headroom, but the limit is still 16A on each individual phase, not an averaged total. Balancing generation across phases is a design decision you make before you ever open the notification form.
Take a common example. A 5.5kW single-phase inverter exceeds 16A on that one phase, so it cannot use G98 at full output. Cap or export-limit it below the threshold and G98 is back in reach. The same array on a balanced three-phase supply could sit inside G98 comfortably. The design choice drives the paperwork.
The list below sets the two routes side by side so you can place a job quickly.
- Single-phase limit: G98 up to 16A, about 3.68kW; G99 above 16A per phase.
- Three-phase limit: G98 up to 16A per phase, about 11kW total; G99 above that.
- Approval: G98 needs none; G99 requires DNO approval before energising.
- Timeline: G98 is notify within 28 days; G99 typically runs to around 45 working days.
- Submission: Both now go through ENA Connect Direct, with DNO portals as a fallback.
How battery storage changes the calculation
Batteries count. Electricity storage devices are treated as micro-generators under G98, and an AC-coupled battery inverter counts toward the combined 16A per-phase total for the premises (1app.energy, 2026). A modest solar array that fits G98 on its own can breach the limit once you add a hybrid or storage inverter.
This is where solar-plus-storage quotes go wrong. Add the inverter ratings, not the panel or cell capacity, and check each phase. If you are specifying a hybrid unit, read our hybrid inverter guide before you size it, because the inverter rating is what the DNO counts, not the battery capacity in kWh.
What evidence do you need before you notify?
You need three things: the type-test evidence, the commissioning detail, and a clear system diagram. Each generator and battery inverter must be on the ENA Type Test Verification Report Register, and you quote its Product ID on the form (ENA, 2026).
A clean single-line diagram saves time on any later query and is expected on more complex jobs. If you are not producing one as standard, our single-line diagram guide sets out what a compliant drawing includes. Keep the type-test reference numbers with the job file, because a wrong or missing Product ID is the most common reason a notification bounces back.
You also confirm the connection point and the MPAN so the DNO can match the notification to the right supply. On sites with existing generation, list what is already connected, because the assessment is cumulative across the premises, not per installation. Missing that step is how a compliant-looking job quietly breaches the limit.
How do you submit a G98 notification in 2026?
Submit through ENA Connect Direct, the platform that digitalises the old paper-based process (ENA, 2026). You notify within 28 days of commissioning, and DNOs do not usually charge a fee for small-scale generation. Expect an acknowledgement within about 5 to 10 working days.
Where a DNO still runs its own portal, that remains a fallback, but Connect Direct is the route to standardise on. In practice the fastest submissions are the ones where the installer has the MPAN, the type-test references and the commissioning date ready before opening the form. Chasing those details mid-application is what turns a 20-minute job into a week of back and forth.
When a G98 job becomes a G99 job
The moment total generation exceeds 16A on any phase, you are in G99 territory, and G99 requires DNO approval before you energise (Northern Powergrid, 2026). That approval typically runs to around 45 working days, so it changes your project timeline, not just your paperwork.
If you expect to cross the threshold, plan the G99 route from the quote stage. Our G99 application guide covers approval, witness testing and export limitation. Some installers deliberately design to sit just under 16A per phase, using export limitation, to keep a job inside the simpler G98 process.
Common G98 mistakes installers make
The recurring errors are avoidable: quoting the wrong Product ID, forgetting that a battery inverter counts toward the limit, and missing the 28-day window. On three-phase jobs, we routinely see generation loaded onto one phase when balancing it would have kept the whole site comfortably inside G98.
Treat the notification as part of commissioning, not an afterthought. File it the same week you energise, keep the acknowledgement with the job pack, and hand the homeowner a copy alongside their MCS installation certificate and other documents. A tidy G98 record also makes any future battery retrofit far easier to reassess against the per-phase threshold.
Handled well, G98 is the easiest compliance step in the job. Tools that keep type-test references, MPANs and commissioning dates in one place, like Reonic, take most of the friction out of the notification. The standard rewards preparation: get the evidence straight before you open Connect Direct and the rest is quick.
Frequently asked questions
Is a G98 certificate the same as an MCS certificate?
No. A G98 notification confirms your generator connects safely to the network within the type-tested limits. An MCS installation certificate confirms the installation meets the microgeneration quality scheme and is what opens access to grants and the Smart Export Guarantee. Most compliant jobs need both, and they serve different purposes in the handover pack.
How long do I have to submit a G98 notification?
You must notify the DNO within 28 days of commissioning the system. Because G98 is a notify-only route, you can energise straight away, but the clock starts at commissioning. Filing in the same week you finish the job is the safest habit and avoids the notification being forgotten once you move on to the next site.
Do I need to pay a fee for a G98 application?
DNOs do not usually charge a fee to process a G98 notification for small-scale generation. The cost to you is time rather than money. Having the MPAN, type-test Product IDs and commissioning date ready before you start keeps a straightforward submission to roughly 20 minutes on Connect Direct.
Can I install solar and a battery under one G98?
Yes, provided the combined inverter output stays at or below 16A per phase. Battery and hybrid inverters count as micro-generators, so you add their rated output to the solar inverter when checking the limit. If the total crosses 16A on any phase, the whole installation moves to the G99 route.
What happens if I skip the G98 notification?
The installation is non-compliant with the connection agreement, even if it works. That can create problems for the homeowner at sale, invalidate aspects of warranty or insurance cover, and damage your standing with the DNO. Notification is quick and free, so there is no practical reason to skip it.
