G98 and G99 applications

Which one your install needs, and what happens next.

The line between the two is one number. Below it you connect and tell the network operator afterwards. Above it you apply and wait for approval before anything is energised. This is where that line sits, which side your install falls on, and what each route actually involves.

Quick check

Do you need a G98 or a G99?

Three questions. It works out the amps per phase and shows you the arithmetic.

Total inverter outputCombined across the whole premises, and including any battery inverter. That last part is what catches people out.

kW

SupplyThree phases raise the ceiling, but only if generation is spread across them.

Single phaseThree phase

Is every inverter fully type tested?On the ENA Type Test Verification Report Register, quotable by Product ID.

YesNot sureNo

G98

This gives you the likely route from the numbers, not a decision. Network operators differ, sites have their own constraints, and the final call is theirs. Nothing you enter leaves your browser.

G98 / G99 route assessment

Indicative route from the figures entered. Not a design or an approval.

Reference: Date: Indicated route:

Input	As entered
Generation
Supply
Type testing
Calculated
Threshold
Working

G98 covers fully type tested micro-generators up to and including 16 A per phase (ENA Engineering Recommendation G98, Issue 2, 10 March 2025). Quoted timings elsewhere are commonly used norms rather than guarantees, and network operators differ. This is an indication for planning a job, not an approval: the operator handling the connection has the final say.

The difference

G98 or G99: one number decides it

Both are ENA Engineering Recommendations covering how generation connects to the low voltage network. The threshold between them is 16 A per phase.

G98 and G99 at a glance. Thresholds are set by the ENA Engineering Recommendations; timings are the commonly quoted norms and vary by network operator.
	G98	G99
Applies to	Fully type tested micro-generators up to and including 16 A per phase	Generation above the G98 threshold, or anything not fully type tested
Roughly	About 3.68 kW single phase, about 11 kW across three phases	Anything larger, and all non-type-tested equipment
Order of events	Connect first, notify after. The install goes ahead, then the network operator is told	Apply first, connect after. Nothing is energised until approval comes back
What you send	A notification recording what was installed and where	A full application, assessed by the network operator
Typical timing	Notification within 28 days of commissioning	Commonly quoted around 45 working days for a decision
Risk to the job	Low. The work is done before the paperwork	Real. The connection date depends on someone else’s queue

Worked examples

Which route a real install takes

The threshold is per phase and it is cumulative across the premises, which is where most of the confusion comes from.

3.5 kW solar PV, single phase

G98

Comfortably under 16 A per phase, and type tested. Install, commission, then notify.

4.5 kW solar PV, single phase

G99

Above roughly 3.68 kW on a single phase, so it crosses the line. Apply before connecting.

3.5 kW solar plus a 5 kW battery

Check carefully

An AC-coupled battery inverter counts toward the same per-phase total as the panels. Solar that passes on its own can push the premises over once storage is added.

10 kW solar across three phases

G98

Three phases raise the ceiling to about 11 kW in total, so this still sits inside G98.

Anything not on the type test register

G99

G98 only covers fully type tested equipment. If the inverter is not on the ENA register with a Product ID, the G98 route is closed regardless of size.

EV charge point or heat pump

Neither

These are demand, not generation, so G98 and G99 do not apply. They still need a network notification, but through the demand route rather than these two.

What goes wrong

Five reasons a G99 application comes back

Almost none of them are electrical.

1

The equipment is not on the type test register

G98 is only open to fully type tested micro-generators. Every inverter needs to appear on the ENA Type Test Verification Report Register and be quoted by its Product ID. Substituting a different inverter on the day, for stock reasons, quietly invalidates the route you applied under.

2

Storage was added to the sum after the fact

The 16 A per phase limit is the aggregate for the premises, not the figure for the panels alone. A battery added later, or quoted as a separate job, can push a compliant solar install over the line without anyone revisiting the paperwork.

3

The phase arrangement is wrong on the form

Per phase means per phase. A three-phase supply raises the ceiling to roughly 11 kW in total, but only if generation is actually balanced across the phases rather than sitting on one.

4

Photographs and documents do not meet the spec

Applications bounce on file sizes, missing serial-number shots and unreadable commissioning certificates far more often than on anything electrical.

5

The notification is late

On the G98 route the work is already done, which makes the notification easy to forget. It is still a requirement, and a missing one surfaces later at the worst moment, usually when the customer applies for an export tariff.

Check the source, and check with your operator. The scope above is set by ENA Engineering Recommendation G98, Issue 2, dated 10 March 2025, which covers the connection of fully type tested micro-generators up to and including 16 A per phase. Quoted timings are the commonly used norms rather than a guarantee, and network operators differ. The recommendations themselves are published by the Energy Networks Association, and applications are submitted through ENA Connect Direct.

Submitting these from the job, not from a second system

installHUB captures the connection data during the site survey and files the notification through ENA Connect Direct without anyone re-keying it, then tracks the operator’s response against the job it belongs to. The survey answers become the application fields.

How DNO submissions work →Surveys that feed the application →Will the supply take it? →MCS certification, and what is changing →Is the work notifiable under Part P? →DNO application checklist →

Questions

G98 and G99, answered

What is a G99 application?+

A G99 application is the request you submit to the network operator before connecting generation that sits above the G98 threshold, or that is not fully type tested. Unlike the G98 route, nothing is energised until the operator has assessed the application and approved it. It is named after ENA Engineering Recommendation G99, which sets out how that connection is made.

What is the difference between G98 and G99?+

The threshold. G98 covers fully type tested micro-generators up to and including 16 A per phase, which is roughly 3.68 kW on a single phase or about 11 kW across three. Below that line you connect first and notify the operator afterwards. Above it, or with equipment that is not fully type tested, you apply under G99 and wait for approval before connecting.

How long does a G99 application take?+

Around 45 working days for a decision is the figure most commonly quoted, but it varies by network operator and by how loaded the local network already is. Treat it as a lead time to plan the job around rather than a fixed date, and confirm the current position with the operator handling the connection.

Does a battery need a G98 or G99 application?+

Battery storage that can export counts as generation, and an AC-coupled battery inverter counts toward the same 16 A per phase total as the solar. That is the most common way a site crosses the line: the panels pass on their own, the battery is quoted separately, and the combined figure has never been checked against the threshold.

Do EV chargers and heat pumps need G98 or G99?+

No. G98 and G99 cover generation. An EV charge point or a heat pump is demand, so it goes through the network operator’s demand notification route instead. It still needs notifying, which is why it is easy to assume the same forms apply.

What happens if the notification is never sent?+

On the G98 route the installation is already live, so nothing fails immediately, and that is exactly why it gets missed. The obligation stands, and the gap usually surfaces later, most often when the customer applies for an export tariff and the supplier asks for evidence the connection was notified.

Where do these applications get submitted?+

Through ENA Connect Direct, the shared portal the network operators use for connection applications and notifications. installHUB submits to it directly from the job, so the survey data becomes the application without being re-keyed.

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