Site Survey, DNO Approval, Grant Administration, and Commissioning for EV Charging Installers

EV charging installation is one of the fastest-growing trades in the UK renewables sector. As of January 2026, there were 116,729 public chargepoints across 45,242 locations in the UK, against a government target of 300,000 by 2030 - a gap that represents several years of funded installation work still to come. For installers, that opportunity comes with real operational complexity: jobs span multiple approval stages, grant administration sits partly in the installer's hands, and commissioning requirements go well beyond a standard electrical installation. Businesses that manage these four disciplines consistently - site survey and load assessment, DNO notification and grid approval, grant administration and invoicing, and commissioning and handover - tend to grow faster and hold margin better than those treating EV jobs as glorified socket installations.

Site Survey and Load Assessment

The site survey is the foundation of every EV charging job. On a domestic installation, it can be completed in under an hour; on a commercial project with multiple bays across an existing car park, it may take a full day and involve coordination with the facilities manager, the building owner, and the Distribution Network Operator. Either way, getting it wrong at the survey stage costs more to fix than any other mistake on the job.

The core deliverable from a site survey is a load assessment: how much additional electrical demand the proposed chargers will place on the existing supply, whether the current infrastructure can support it, and whether a DNO notification or formal grid application is needed. Surveyors need to check the incoming supply rating, the condition of the main distribution board, available consumer unit capacity, and cable routing options between the supply and proposed charger locations.

On commercial sites, the survey should also establish how the chargers will be used in practice. Multiple chargers operating simultaneously at peak periods draw significantly more current than a single unit, and load management architecture - which balances demand dynamically across bays - needs to be specified at the design stage, not retrofitted. A site survey that misses peak concurrency requirements leads to a commissioning problem, an unhappy customer, and a return visit.

For businesses running multiple surveyors, the key operational discipline is consistency: a standard survey checklist, a record of each finding tied to the job, and a clear sign-off before any design work begins. Survey costs are real costs and should be captured against the job record. On larger commercial projects, a formal written survey report supports the quote, the DNO application, and the customer conversation about scope and budget.

DNO Notification and Grid Approval

The Distribution Network Operator (DNO) process is the part of an EV charging job that most frequently causes timeline problems for installers. Understanding when a simple notification is sufficient and when a formal grid application is required - and planning the job timeline accordingly - is what separates experienced EV installers from those who learn the hard way.

For domestic smart chargers, the relevant framework is Engineering Recommendation G100, which sets out notification requirements for connection of EV charge points. Most 7kW single-phase domestic installs fall within G100's notification-only category, with the DNO informed but not required to approve the installation before work begins. Allow 2-10 working days for the notification to be processed. For more complex domestic scenarios - vehicle-to-home (V2H) setups that involve export, or homes approaching the DNO's local network capacity limits - a formal application may be required.

Commercial installations are a different matter. Because commercial EV charger banks can draw significant power from the local network, many require a formal DNO connection application before work can proceed. This can take several weeks, and on sites needing network reinforcement it can extend to several months. The practical discipline for installers is to initiate DNO engagement as early as possible - ideally immediately after the site survey - rather than waiting until the customer is ready to proceed. A job that is commercially agreed but stuck waiting for DNO approval is a scheduling problem and a cash flow problem simultaneously.

The DNO approval stage also affects WCS grant administration timing. The grant voucher has a 180-day validity window from the date of issue. On a straightforward domestic job, 180 days is generous. On a commercial installation requiring formal grid approval, groundworks, and significant infrastructure work, that window can close before the job is finished - particularly if the DNO process takes 8-12 weeks and groundworks are delayed by weather or site access. Businesses should track voucher expiry dates as active job milestones, not background admin.

Grant Administration and Customer Invoicing

The Workplace Charging Scheme is the primary funding mechanism for commercial EV charging in the UK. From 1 April 2026, the grant increased from £350 to £500 per socket, covering up to 75% of eligible costs, with a maximum of 40 sockets per applicant. The scheme has been extended until 31 March 2027 - OZEV has described this as the final year - making 2026/27 the last grant-supported window before businesses and installers move to a fully commercial funding environment.

For installers, the WCS creates a specific invoicing obligation. Claims must be submitted by an OZEV-approved installer on the applicant's behalf, and the grant is deducted directly from the installer's invoice rather than paid separately to the customer. This means the installer raises an invoice showing the full installation cost, applies the grant deduction, and the customer pays the net amount. Managing this correctly requires the business to track the voucher amount, the approved socket count, and the claim deadline per job - not across the business as a whole, but per installation.

The most common invoicing problems on WCS jobs are: claiming before the voucher is confirmed; installing before the customer has received eligibility notification from OZEV; and failing to submit the claim within the allowed window after installation. The claim must be submitted promptly after commissioning - installers operating on monthly billing cycles can miss claim deadlines if the job closes late in a billing period.

For non-WCS commercial jobs - larger multi-site installations, fleet depot projects, or work for organisations that don't qualify for the scheme - the invoicing structure is typically deposit on order, a stage payment on completion of groundworks and first fix, and a final invoice on commissioning. Agreeing the payment schedule at the quote stage and linking each payment to a specific completion milestone avoids the dispute over whether a stage has been reached that is common on larger EV projects.

Commissioning, Certification, and Handover

EV charger commissioning goes beyond the electrical test that closes a standard installation job. A commissioned EV system requires functional testing of the charger unit itself, verification of smart charging compliance, configuration of any network management software, testing of load management where multiple units are installed, and confirmation that the unit appears correctly on any charge point operator platform being used.

The certification obligations reflect this scope. Installers self-certifying under a Part P scheme - NICEIC, NAPIT, or Stroma - must issue the relevant electrical installation certificate covering the dedicated circuit and associated works under BS 7671 Section 722. Where the charger is OZEV-approved and forms part of a WCS claim, the installer must also be on the OZEV-approved installer register. These are separate registration requirements, and operating on WCS jobs without OZEV status invalidates the grant claim.

From 1 October 2026, the qualification landscape shifts further. Updated Electrotechnical Assessment Specification (EAS) rules move toward requiring each individual installer physically fitting a charge point to hold their own Level 3 EV qualification - not just the firm's qualified supervisor. Businesses expanding their EV installation teams ahead of this deadline need to account for this in their training programmes and workforce planning.

Customer handover on a commissioned EV job should include the installation certificate, charger documentation, user instructions for the specific unit installed, confirmation of the smart charging configuration, and any network access credentials if the charger is connected to a charge point management system. For WCS-funded jobs, the customer also needs confirmation of what has been submitted on their behalf, including the voucher claim reference. Building a standard handover pack into the commissioning process - rather than assembling it job by job - is the difference between a professional close and a follow-up call three weeks later asking for a document the customer can't find.

Managing the EV Job Pipeline as the Business Scales

Individual job discipline matters. But as EV charging businesses grow from a handful of installs per month to 20, 30, or more, the administrative load compounds quickly. Each job has its own DNO reference, OZEV voucher number, Part P notification, commissioning record, and billing schedule. A business managing that across email threads, shared spreadsheets, and a generic accounting system will start to drop things - missed claim windows, invoices sent without the voucher deduction applied, handover packs sent to the wrong customer.

The practical answer is a job record that captures the DNO status, voucher number and expiry date, billing milestones, and commissioning status for each installation as live, trackable data rather than as documents stored in folders. When a surveyor completes a commercial site assessment, that finding updates the job directly. When the DNO confirmation arrives, the job status changes and the next milestone becomes active. When commissioning is complete, the handover pack is assembled from the documents already attached to the job and the WCS claim is triggered.

Zigaflow gives EV charging businesses this structure as part of the quote-to-invoice workflow. Quotes are linked to jobs, purchase orders for equipment are raised against the job record, and invoicing follows the payment milestone schedule agreed at the quote stage. For WCS jobs, the grant deduction is handled within the invoice, and the job doesn't close until commissioning and certification are recorded as complete. Businesses using this approach find that growing from 15 to 50 installs per month doesn't require proportionally more admin staff - it requires the same process running at higher volume.

The EV charging market in the UK has years of funded growth ahead of it. The businesses positioned to capture that growth consistently are those that have already built their operational processes to handle the complexity - not those still discovering it one install at a time.