Switching DNO region: what changes for your install pricing and lead times

In short

Every DNO sets its own connection fees and timescales, and what works in Yorkshire can cost more and take longer in the South West. Before pricing a job in a new DNO area, confirm the regional charging statement and build the programme from that network's actual lead times.

When a job crosses into a different distribution network operator's territory, the installer's pricing assumptions, programme, and paperwork all change - even if the system design is identical. The same 100 kWp commercial roof that connects in 13 weeks in Yorkshire can take 20 weeks in the South West, and the connection offer expenses in one region may be three times those in another. For an installer running jobs across more than one DNO area, a single national quote template and a single lead time in the programme are two guaranteed ways to lose margin or miss a commissioning date.

Why each DNO region is a different operating environment

The UK has six licensed DNOs: UK Power Networks (London, East of England, South East), National Grid Electricity Distribution (Midlands, South West, South Wales), Scottish and Southern Electricity Networks (Scotland and parts of central/southern England), Northern Powergrid (North East, Yorkshire), Electricity North West (Greater Manchester and the North West), and SP Energy Networks (central Scotland, Merseyside, and Cheshire). Each holds a regional monopoly and sets its own charging statement, portal, technical contacts, and processing capacity.

This matters because G99 - the engineering route required for any system above 16 amps per phase, roughly 11 kW on a three-phase supply - is not a national process with a single price list. The DNO reviews the application against the capacity available on its specific local network, and the cost it charges reflects its own asset base, not a benchmark set elsewhere. An installer accustomed to SSEN's rules (which do not charge connection offer expenses below 50 kVA) will find the numbers look different at NGED, where published assessment and design fees run from £187 for a single small generator to £1,674 for LV generation above 50 kVA, and to £3,184 for high-voltage work above 1 MVA. SP Energy Networks, meanwhile, carries some of the highest reported admin fees for installers - £250 to £750 in some cases. None of these figures is wrong: they reflect different regional charging statements, and an installer pricing a job in an unfamiliar DNO area without checking the current statement will absorb the difference.

The timeline gap that breaks a national programme

On paper, every DNO owes a generation quotation within 45 working days of receiving a valid G99 application, with an £85-per-working-day payment for each day of delay beyond that. In practice, the range is far wider. Northern Powergrid, which covers the North East and Yorkshire, can issue fast-track approvals in a single day in straightforward cases. Standard G99 applications with DNOs in areas of high solar density - the South West in particular - can run to four to six months where grid constraint triggers a capacity study.

Across the six DNOs, connection offer timescales for commercial solar (100 kW to 1 MW) range from 12 to 20 weeks under current conditions: UK Power Networks runs 13 to 18 weeks; NGED 14 to 20; SSEN 12 to 16; Northern Powergrid 12 to 15; Electricity North West 14 to 20; SP Energy Networks 13 to 17. Where reinforcement is triggered - because proposed generation exceeds the thermal or voltage limits of the local feeder - those timescales can extend by months and connection costs jump sharply. A typical LV connection with no reinforcement costs £8,000 to £35,000 for a 100 kW to 1 MW system, but reinforcement can push that to £30,000 to £150,000 or beyond.

An installer who builds a programme around a SSEN-region job on the assumption that the same timeline applies in a constrained urban UKPN area will miss the commissioning date the customer was quoted. The DNO is almost always the longest item on the commercial solar critical path - longer than procurement, longer than the physical install. That is the variable that changes most when crossing a regional boundary.

What region-specific pricing and scheduling actually looks like

A firm operating across renewables installs in multiple DNO areas should treat each region as a distinct cost and lead time environment, not a variant of a single national template.

On the cost side, the quote for every G99 job should carry the DNO application fee as a named line item - confirmed against the current charging statement for that specific DNO, not estimated from a previous job in a different region. Connection charges, where they apply, should be shown as provisional sums tied to the actual connection offer rather than buried in a contingency. Witness testing fees (around £957 plus VAT per visit in most DNO areas, though rates vary by network) should be shown separately. These are real costs that will hit a customer invoice one way or another; the choice is whether they are visible at quote stage or discovered later.

On the programme side, the G99 application clock should start as soon as the survey is complete - not when the customer signs. A G99 lodged the day the deposit lands runs in the background while the customer finalises finance and the team procures equipment. One lodged in the week before scaffolding goes up becomes the bottleneck. In a DNO area with a 16 to 20-week connection offer timeline, that difference determines whether the customer sees commissioning in Q1 or Q2.

The DNO is almost always the longest item on a commercial solar project's critical path. That is also the variable that changes most when crossing a regional boundary.

Tracking where each job's G99 application sits - which DNO, what stage, when the 45-working-day clock expires - is the kind of milestone visibility that project tracking is built for. An installer running five concurrent G99 applications across three DNO regions cannot manage that from a shared inbox. The ones that slip are the ones without a named stage, a current status, and a flag when the clock is close to expiring.

The practical test for any multi-region business

Before pricing a job in an unfamiliar DNO area, three checks take less than an hour and prevent expensive surprises. First, identify the DNO and pull its current charging statement - fee schedules change and differ enough between regions that last year's number from a different network is not a safe estimate. Second, check the DNO's online grid capacity heatmap (UKPN, NGED, SSEN, and the others all publish them) to assess whether the site sits in a constrained zone that may trigger a capacity study and delay. Third, build the programme from the DNO's current connection offer timescale for the type of system being installed - not from a regional average.

The firm that prices and schedules region-by-region, treats DNO fees as line items rather than overhead, and submits G99 applications at survey stage rather than install stage will consistently deliver more accurate quotes and more reliable commissioning dates. In a market where delays are the most common customer complaint, that operational discipline is the actual differentiator.

Sources

• G99 Application UK: Avoid Rejection - Costs by DNO & 2026 ReformsSolarGridCheck · accessed 2026-10-11
• G99 Application: How to Get DNO Approval in 2026Reonic · accessed 2026-10-11
• G99 Application for Warehouse Solar PV: The 2026 Complete GuideSolar Panels for Warehouses · accessed 2026-10-11
• G99 application UK fees and timescalesAxiom Eco Homes · accessed 2026-10-11