Solar energy is expanding rapidly across the United Kingdom. As the government accelerates its target of 70 GW of solar capacity by 2035, thousands of installers are deploying rooftop and ground-mounted systems across England, Scotland, Wales, and Northern Ireland. Behind every successful installation, however, lies a sequence of regulatory and technical approvals that solar installers, EPC contractors, and project developers must navigate with precision.

Understanding solar permit services in the UK is not simply a compliance exercise. It is a competitive advantage. Faster approvals mean faster installations, quicker revenue, and stronger client relationships. This guide breaks down every stage of the UK solar permit process — from planning permission and DNO grid connection applications to MCS certification — so your team can move from proposal to energisation without unnecessary delays.

What Are Solar Permit Services in the UK?

Solar permit services in the UK encompass the full suite of regulatory approvals, technical documentation, and compliance submissions required before a solar PV system can be legally installed and connected to the grid. Unlike the United States, where a single permit plan set submitted to the Authority Having Jurisdiction (AHJ) is the central deliverable, the UK regulatory landscape is distributed across several bodies, each governing a different aspect of the installation.

These approvals include planning permission confirmation or a permitted development assessment, grid connection notification or application through the Distribution Network Operator (DNO), MCS certification of the installation, and in some cases a building regulations compliance submission. Each requirement carries its own timeline, documentation standard, and consequence for non-compliance. Solar permit services manage all of these on behalf of the installer, ensuring every project advances through the pipeline without rework or rejection.

Solar PV panels on a UK residential pitched roof — qualifying for permitted development in most cases.

Step 1: Planning Permission & Permitted Development

The first regulatory question for any UK solar project is whether planning permission is required. For the majority of residential installations, the answer is no. Under Part 14 of the General Permitted Development Order (GPDO), most rooftop solar PV systems qualify as permitted development, meaning no formal planning application is needed before installation can begin.

To qualify as permitted development on a residential pitched roof, the installation must meet specific physical conditions. Panels must not protrude more than 200mm above the roof slope, must not extend above the highest point of the roof, and must not be installed on the principal elevation of a property in a designated area such as a conservation area, Area of Outstanding Natural Beauty (AONB), or National Park.

Listed buildings are excluded from permitted development rights entirely and always require Listed Building Consent before any solar installation can proceed. For flat roof installations, permitted development applies provided the panels do not protrude more than 0.6 metres above the roof surface and do not exceed the highest point of the building.

A significant regulatory change took effect in December 2025. The Infrastructure Planning (Onshore Wind and Solar Generating Stations) Order 2025 raised the Nationally Significant Infrastructure Project (NSIP) threshold from 50 MW to 100 MW. Projects between 50 MW and 100 MW now use the faster local planning authority route rather than the Development Consent Order (DCO) process, saving developers up to £2 million and up to twelve months in delivery timeline. Only solar farms exceeding 100 MW continue to require a Development Consent Order.

When there is any uncertainty about whether an installation qualifies as permitted development, the installer or homeowner can apply to the local authority for a Lawful Development Certificate (LDC). This formal determination costs approximately £129 and provides written confirmation that no planning application is required. Solar permit services providers routinely obtain LDCs as part of the pre-installation compliance review.

A professionally prepared solar design package includes site plans, electrical diagrams, and shading analysis.

Step 2: Technical Design & Permit Documentation

Once the planning position is confirmed, the technical design phase begins. In the UK, solar permit services coordinate this phase end-to-end, producing documentation comparable to the permit plan set produced for US AHJ submissions, though tailored to British Standards and UK grid requirements rather than NEC code.

A professionally prepared UK solar permit services documentation package typically includes a site plan showing panel layout, roof pitch, and orientation; single-line electrical diagrams; inverter specifications; mounting system details; shading analysis; and a string configuration schedule. Where a structural assessment is needed — particularly for older or non-standard roof types — a structural engineer confirms that the roof can bear the additional load.

The quality and completeness of this technical package directly determines the speed of downstream approvals. Inaccurate or incomplete designs lead to DNO queries, MCS audit failures, and costly installation delays. Engaging a specialist solar permit services provider ensures the documentation meets every applicable standard and is ready for submission at each stage without revision cycles.

UK Distribution Network Operators (DNOs) are responsible for managing local electricity grids — all solar exports must be notified or approved by the relevant DNO.

Step 3: DNO Grid Connection — G98 and G99

All grid-connected solar PV installations in the UK must be notified to or approved by the local Distribution Network Operator (DNO). DNOs are the companies responsible for distributing electricity from the National Grid to homes and businesses across the country. The regulatory framework governing these applications is established by the Energy Networks Association (ENA), and the two primary application types are G98 and G99.

G98 — Connect and Notify

G98 applications apply to solar installations where the inverter capacity does not exceed 3.68 kW per phase (16 amps per phase). These are commonly described as connect-and-notify installations. The installer proceeds with the installation and submits a completed G98 notification to the DNO within 28 days of the system being commissioned. Solar permit services handle this notification as a standard step, making it a seamless part of the overall project workflow at no additional cost to the applicant — the standard route for most residential solar projects in the UK.

G99 — Prior Approval Required

G99 applications are required for any system where the inverter capacity exceeds 3.68 kW per phase. Unlike G98, a G99 application must be submitted and approved by the DNO before the installation can proceed. Larger systems carry greater potential to affect local grid stability, which is why the DNO reviews the application in detail before granting connection permission.

Assessment fees for G99 applications range from £500 to £2,500 for high-voltage connections and £3,000 to £8,000 or more for extra-high-voltage connections. These fees are non-refundable. Each DNO operates its own portal and forms — UK Power Networks and National Grid Electricity Distribution have well-developed online portals, while Northern Powergrid and Electricity North West still use email-based submissions for some application types. Navigating these differences is a core part of what professional solar permit services deliver for commercial projects.

For commercial solar systems, G99 is almost always required. Even a 50 kW commercial rooftop system triggers the G99 process. Without DNO approval, the system cannot export electricity to the grid and the operator cannot access an export Meter Point Administration Number (MPAN), the 13-digit identifier that enables Smart Export Guarantee (SEG) payments. Experienced solar permit services teams prepare and submit G99 applications as part of a coordinated permitting workflow, reducing the risk of delays caused by incomplete submissions.

MCS certification is the gateway to Smart Export Guarantee (SEG) payments — unlocking export income for solar system owners.

Step 4: MCS Certification

MCS — the Microgeneration Certification Scheme — is the quality assurance framework that governs small-scale renewable energy installations in the UK. MCS certification is required to access government incentive schemes, most importantly the Smart Export Guarantee, which pays solar system owners for surplus electricity exported to the grid. Reliable solar permit services ensure MCS documentation is prepared correctly alongside planning and grid connection submissions.

For an installation to receive MCS certification, both the installation company and the components used must be MCS approved, the system must be installed by an MCS-registered contractor, and the installation must comply with MCS installation standards. Following completion, an MCS certificate is issued and the project is registered on the national MCS database.

It is important to understand that MCS certification does not check planning status. Compliance with permitted development rules or a granted planning permission is a separate responsibility that falls on the installer and the property owner. Professional solar permit services handle both compliance streams in parallel to ensure no gap exists between planning, grid connection approval, and certification.

Electrical compliance certificates under Part P of the Building Regulations must be retained — they are required during property sales and mortgage assessments.

Step 5: Building Regulations

Building regulations compliance for solar PV in England is generally straightforward for standard rooftop installations. Most solar PV electrical work is self-certified by a registered competent person under Part P of the Building Regulations (Electrical Safety) or by a NICEIC, NAPIT, or HETAS registered electrician, which removes the need for a separate building regulations application in the majority of cases.

In Scotland, the Building (Scotland) Regulations apply, and a building warrant may be required for larger or structurally complex installations. In Northern Ireland, Building Regulations approval follows a broadly similar structure under the Building Regulations (Northern Ireland) Order. A competent solar permit services provider assesses which building regulations notifications or approvals are needed on a project-by-project basis and obtains the relevant certifications accordingly.

It is also worth noting that any electrical work associated with a solar installation — including inverter connections, new circuits, or consumer unit modifications — must comply with BS 7671 (the IET Wiring Regulations). Where the work is carried out by a registered competent person, a Building Regulations compliance certificate is issued directly to the homeowner or building owner upon completion. Retaining this certificate is important, as it may be requested during a property sale or by mortgage lenders reviewing the installation’s compliance status. This documentation is routinely compiled by solar permit services teams as part of a complete project handover pack.

How One Place Solar Supports UK Solar Projects

One Place Solar provides end-to-end solar permit services for installers and EPC companies operating across the UK. Our team prepares technically precise design packages tailored to UK standards, coordinates DNO application documentation for both G98 and G99 submissions, and ensures your projects are permit-ready from the first stage through to energisation.

With a 98 percent approval rate across global markets and a centralised project management platform that gives your team full visibility at every stage, One Place Solar eliminates bottlenecks and accelerates project delivery. Our solar permit services are backed by an AI-assisted quality verification process that reviews every design before submission, reducing revision cycles and keeping your pipeline moving.

Whether you are an established UK solar installer scaling your portfolio or an EPC company entering the UK market for the first time, our team brings the technical depth and regulatory knowledge needed to make every project a smooth one. Reach out today to discuss your UK project requirements and discover what professional solar permit services can do for your business.