Free DNO Application Checker
Check whether you need a G98 notification or G99 application for your solar, battery, or generation installation. Enter the installation postcode and system details to find your DNO and understand the process.
DNO Application Checker
Check whether you need a G98 notification or G99 application
A DNO application checker helps UK solar and clean tech installers determine whether a generation connection requires a G98 notification or G99 full application under the Engineering Recommendations published by the Energy Networks Association (ENA). The decision depends on the total generation capacity at the property and the phase type of the electrical supply. In Payaca, DNO applications are integrated directly into your workflow via ENA Connect, with automatic status tracking and notifications. For compliance documentation including MCS certificates and handover packs, see our compliance features.
G98 vs G99: How it works
When connecting generation equipment (solar panels, batteries, wind turbines, etc.) to the UK electricity grid, installers must either notify or apply to the local Distribution Network Operator (DNO). The process depends on the total generation capacity at the property.
G98 (notification): For systems up to 3.68 kW on a single-phase supply or 11.04 kW on three-phase. You install first and notify the DNO within 28 days of commissioning. There is no fee, and the DNO typically responds within 4 weeks.
G99 (full application): For systems above the G98 thresholds. You must apply to the DNO before installing. The DNO assesses the impact on the local network and may require grid reinforcement works. Assessment fees range from £500 to £2,500 depending on DNO and project complexity, and the process typically takes 8–12 weeks.
Cumulative capacity: These thresholds apply to the total generation at the property. If a site already has 2 kW of solar panels and you're adding 2 kW more, the combined 4 kW exceeds the 3.68 kW single-phase threshold - meaning a G99 application is required even though the new installation alone would be under the limit.
Battery storage: Assessed on the inverter rating (maximum export power in kW), not the battery capacity in kWh.
Frequently asked questions
What is the difference between G98 and G99?
G98 is a simple notification process for smaller installations (up to 3.68 kW single-phase or 11.04 kW three-phase). You install first and notify your DNO within 28 days. G99 is a full application process for larger systems -you must apply to your DNO and receive approval before starting the installation. G99 involves an assessment fee (typically £500–£2,500) and takes 8–12 weeks.
What is a DNO?
A Distribution Network Operator (DNO) is the company responsible for maintaining the local electricity distribution network in your area. There are six DNOs covering Great Britain (plus NIE Networks in Northern Ireland). When connecting generation equipment like solar panels or batteries to the grid, you must notify or apply to the relevant DNO.
How long does a G99 application take?
A typical G99 application takes 8–12 weeks, but complex cases or those requiring grid reinforcement can take up to 6 months. The DNO has 45 working days to provide a connection offer once they have all the required information. Assessment fees range from £500 to £2,500 depending on DNO and project complexity. Grid reinforcement, if required, is an additional cost.
How is battery storage assessed?
Battery storage is assessed on its inverter rating (maximum export power in kW), not the battery capacity in kWh. For example, a 10 kWh battery with a 3.6 kW inverter would be assessed as 3.6 kW for G98/G99 purposes.
What does cumulative capacity mean?
G98 and G99 thresholds apply to the total generation capacity at a property, including any existing solar, battery, or other generation equipment already connected. If a property already has 2 kW of solar panels and you want to add 2 kW more, the total 4 kW exceeds the 3.68 kW single-phase G98 threshold, requiring a G99 application.
What is export limiting (G100)?
G100 is not a separate application type -it refers to an export limiting device that a DNO may require as a condition of approving a G98 or G99 application. This is common in areas where the local grid has limited capacity for additional generation. The device limits how much power your installation can export to the grid.
Does Northern Ireland have the same rules?
No. Northern Ireland has its own electricity network managed by NIE Networks and uses different connection processes. While the general principles are similar, you should contact NIE Networks directly or visit nienetworks.co.uk for guidance on connecting generation in Northern Ireland.