Filing a DNO notification after a solar install
In short
Qualifying domestic solar and battery systems need a G98 notification to the DNO within 28 days of commissioning, with no prior approval. Collect the MPAN, equipment references and existing generation details at survey so you can file in minutes.
- A qualifying domestic solar or battery system needs a G98 notification within 28 days of commissioning, not a prior application.
- Inverter AC rating, not panel kWp or battery kWh, decides whether you stay within the 16A per phase G98 limit.
- Collect the MPAN, equipment serial numbers, type-test references and existing generation details at survey.
- Treat the notification as a job completion gate and keep the acknowledgement in the customer handover pack.
Most domestic solar and battery installs only need a G98 notification filed within 28 days of commissioning. Collect the right details at survey and you can file in minutes, and avoid a G99 application you never needed.
Yes, you need to tell the distribution network operator (DNO) about almost every solar or battery install you commission in Great Britain, and the deadline for a standard domestic system is 28 days from commissioning. For a qualifying system that meets the G98 criteria, this is a notification after the fact, not an application before it. There is no approval to wait for and no fee from the DNO. The time sink comes when an installer reaches the end of a job without the right details and has to chase the customer, the inverter datasheet and the meter number. Collect those at survey and the filing takes minutes.
When G98 notification applies, and when it does not
G98 is the fit-and-notify route for fully type-tested generation of up to 16A per phase at low voltage. At a nominal 230V that is 3.68kW per phase, so 3.68kW on a single-phase supply and 11.04kW across three phases. The figure that counts is the rated AC output of the inverter, not the DC peak rating of the panels in kWp. A 5kWp array on a 3.68kW inverter can still qualify. The same array on an unrestricted 5kW single-phase inverter will normally need a G99 application.
Batteries are judged the same way. Classification follows the inverter rating, not the kWh capacity, but the whole installation is assessed, including any generation or storage already on site. Adding a battery to an existing array can push the combined system out of G98, so check the earlier paperwork before you quote.
National Grid Electricity Distribution lists further conditions. Grid interface protection must be installed to local standards and tested, the system must shut down in a power outage, and a lockable isolation switch must be fitted. A circuit diagram must be displayed on site. The installer must also not have commissioned other generation in the same local area within the last 28 days or plan to do so in the next 28 days. Install several systems on one street in a month and you may be pushed towards G99 anyway.
Do not size by panel count
A quote that sizes on kWp alone can trigger a G99 application nobody planned for. Decide the inverter rating at design stage, and write the G98 or G99 route onto the quote.
What to collect at survey
Most notification delays are missing information, not difficult forms. Using the National Grid form as a guide, you will need the device reference numbers of any new or existing generation, the site postcode, and installer and customer contact details. The MPAN is generated automatically on that form, but it is worth having to hand. In practice, add the inverter and battery model and serial numbers, the phase count, the commissioning date and the type-test reference from the manufacturer's datasheet.
Capture all of this on the survey form, not from memory afterwards. If you run surveys on a phone or tablet, a digital form with required fields means the job cannot move to design until the MPAN photo and existing-generation question are answered. Our eForms app does this on site, and the answers stay attached to the job.
Confirm the route at survey
Record the supply phase count, any existing solar, battery or EV generation, and the proposed inverter rating. Compare the total against 16A per phase. If it is at or under, plan for G98. If not, start a G99 application before you order equipment.
Identify the DNO for the postcode
Great Britain is split into 14 licence areas run by six DNO groups, and which one serves a property is set by location, not by the customer's energy supplier. Look the postcode up on the Energy Networks Association tool or the MPAN prefix, and note the operator on the job. Each has its own portal or form.
Capture the equipment details
Log the make, model and serial number of every inverter and battery, along with the manufacturer's type-test reference. Photograph the data plate on site. These references are what the DNO form asks for, so they must match the installed kit, not the quote.
Commission and record the date
The 28 days run from commissioning, the day the system is first switched on and operating. Write that date on the job record on the day, not when you file. Check the protection settings and complete the commissioning checklist before you leave.
File the notification online
Use the DNO's online form where one exists. National Grid, for one, quotes around 10 to 15 minutes and gives instant acknowledgement. If you cannot file online, the downloadable G98 Form B covers a single premises and Form A covers multiple premises, and both can be emailed or posted with supporting documents.
Save the acknowledgement to the job
Keep the confirmation email and reference number with the job record and in the customer's handover pack. The customer may need them for insurance, a smart meter fitting, export payments or a house sale.
Close the job only when the filing is done
Treat the notification as a job completion gate, alongside the certificate and customer sign-off. A job that is invoiced but unfiled is a job where the 28 day clock is still running.
Making the filing routine
The detail that wastes the most time is not the form but who is responsible. Decide who files, and make it a task with a due date at the point the job is commissioned. Setting the task up in a job management system such as Zigaflow jobs lets you set a deadline of 28 days less a safety margin of a week, and flag it if it is still open.
Generating the documents is the second repeated task. If your handover pack, circuit diagram and customer copy of the notification are produced from document templates, the details captured at survey fill them in without retyping. This is how renewable installers working across the renewables sector keep admin to minutes per job rather than an hour.
Add a seven day buffer
Set the internal due date at 21 days, not 28. That leaves time to correct a mismatched serial number or a missing MPAN before the real deadline passes.
Mistakes that turn a notification into an application
Three errors recur. The first is quoting on panel capacity and then fitting a larger inverter than agreed, which moves the job into G99 after the equipment is on the roof. The second is overlooking existing generation at the property, since the DNO assesses the combined system. The third is treating an export limit as a route to G98. A limitation scheme under G100 controls power flow, but it does not by itself make a larger inverter qualify for the simpler route, as industry guidance explains.
Rules and forms vary by DNO, and this guide describes practice in Great Britain. Check the current guidance from the operator serving the site before filing. Outside Great Britain, grid connection rules differ, so use the local network operator's process.
Sources
- Micro generation single (G98)National Grid Electricity Distribution · accessed 2026-10-17
- G98, G99 & G100 Explained: Solar and Battery ConnectionsRenew-Able Solutions · accessed 2026-10-17