Service Contracts, Fault Management, and Maintenance Billing for Commercial EV Charging Installers

Most commercial EV charging installers build their business around the installation phase - the survey, the DNO application, the equipment procurement, and the commissioning sign-off. But as an installer's portfolio of completed sites grows, a second operation quietly emerges alongside it: the ongoing service, fault response, and maintenance business that those installed assets generate. Handling that second operation with the same operational discipline as the first one is where many installers start to lose money, lose clients, or both.

BEVs accounted for more than 22% of new car registrations in the UK in 2025. Commercial sites that installed two or three charge points three years ago are now asking installers to add more, to take on service agreements, and to guarantee response times. For installers who have structured their business around one-off installation jobs, the shift to contract-based service revenue requires a different set of operational disciplines - from how service agreements are scoped and priced, to how fault calls are logged, escalated, and billed.

What a Commercial Service Agreement Actually Covers

A commercial EV charge point service agreement is not the same as a manufacturer's warranty extension. It is a contract between the installer and the site operator that defines exactly what the installer will do, how quickly, and at what cost. Getting that definition right at the outset prevents the two most common disputes: what is included in the annual fee, and what triggers a separate call-out charge.

A well-structured commercial service agreement typically covers four areas. First, a scheduled annual inspection: a site visit to carry out an EV circuit safety and integrity check tested in accordance with BS7671, a manufacturer function test on each charge point unit, and a visual safety inspection of mountings, cabling, and weatherproofing. Second, firmware and software updates, applied remotely or on-site, to keep charge points compliant with the OCPP version specified in the site's back-office management system. Third, a defined number of reactive call-outs per year included in the contract price - commonly four to six visits - with additional call-outs billed at a fixed rate. Fourth, a telephone and online fault-reporting service with defined response times: typically a four-hour remote diagnostic response and a 48-hour on-site response for faults that cannot be cleared remotely.

What the agreement should explicitly exclude is equally important. Component replacement costs, damage caused by vandalism or vehicle impact, and faults arising from a client's network connectivity failure are common exclusions that must be written into the agreement, not left for a conversation after a dispute arises. Annual maintenance packages in the commercial market start from around £20 + VAT per month per charge point, rising significantly for rapid chargers rated at 50kW and above, where the equipment cost and regulatory obligations are higher.

The 99% Uptime Regulation and What It Means for Service Operations

The UK's Public Charge Point Regulations 2023 introduced a binding 99% average annual uptime requirement for all rapid charge points rated 50kW and above. The first full compliance year was 2025, with reporting due to the regulator in January 2026. Failure to meet the threshold carries penalties of up to £10,000 per network, and operators are also required to provide a 24/7 telephone helpline and publish their reliability data openly.

For commercial EV charging installers who hold service contracts on rapid charge point estates, this regulation changes the nature of the obligation. A client site running six 50kW rapid chargers under a service contract is now subject to an auditable uptime standard. If connectivity failures, unresolved faults, or slow response times push the site below the 99% threshold, the site operator faces the penalty - and will look to the service contractor to explain why the agreed response times were not met.

The data behind that 99% floor is more demanding than it appears. ChargerHelp's 2025 analysis of millions of real sessions found that reported uptime across major networks sat between 98.7% and 99.9%, yet only about 71% of charging attempts actually succeeded. The gap exists because a charger can report itself as "available" while still failing to complete a session: EV-to-charger communication faults caused about 47% of technical failures, and connector-locking faults caused about 44%, across a sample of roughly 13 million sessions. More than a third of those failures happened on equipment that a dashboard showed as online.

The practical implication for installers is that logging a site visit as complete is not the same as confirming that charge points are delivering successful sessions. Service contracts on rapid charge point estates should include a session-success monitoring requirement, not just a hardware uptime check, if the installer is to meet their obligations under a well-drafted agreement.

Fault Logging, Escalation, and Response Discipline

The moment a fault call comes in from a commercial client, the clock starts. A client whose staff or customers cannot charge may be losing productivity, parking income, or compliance standing. The installer's fault management process needs to handle three stages cleanly: receiving and logging the fault, completing a remote diagnostic check, and dispatching an engineer if the fault cannot be cleared remotely.

Fault logging is where many smaller installer operations create problems for themselves later. A fault call taken by phone, captured only in a team member's memory or a chat message, and passed informally to an engineer produces no audit trail. When the client asks why the fault took 36 hours to resolve rather than the 48-hour maximum in the agreement, there is no timestamp to refer to. When a fault recurs three weeks later and the client asks what was done the first time, there is no record to consult.

A structured fault log for each site should capture the fault report time, the reporting method (phone, portal, email), the initial remote diagnostic outcome, the dispatch decision and time, the engineer arrival time, the fault diagnosis, the action taken, any parts ordered, and the resolution confirmation. That record serves three purposes: it supports the call-out invoice, it provides the evidence trail if a client disputes the response time, and it builds the service history for each charge point that informs future maintenance decisions.

Remote diagnostic capability matters because many charge point faults can be resolved without a site visit. Firmware errors, OCPP session lock-ups, and tariff configuration issues can often be cleared from the back-office management system in minutes. If the service agreement charges separately for call-outs, the ability to resolve a fault remotely saves the client a charge-out cost and demonstrates competence. Installers who have not invested in back-office platform access for the sites they maintain are giving up that capability and creating unnecessary engineer dispatches.

Escalation rules should be written into the internal process, not left to judgment on the day. If remote diagnostics cannot clear a fault within four hours, the rule should be automatic engineer dispatch. If a dispatch engineer arrives and cannot resolve the fault due to a component failure, the rule should be immediate parts ordering with a confirmed delivery date communicated to the client before the engineer leaves site. Clients tolerate faults; they do not tolerate uncertainty about when the fault will be fixed.

Preventive Maintenance Scheduling and Documentation

Planned maintenance visits are the predictable, schedulable part of a service contract operation. They should be, but they are also the part most likely to drift when an installer is busy with new installations. A planned visit booked for March gets pushed to May, and by August has not happened at all. At renewal time, the client has not received the annual inspection they paid for, and the installer has no documentation to show they met the contract terms.

The fix is to schedule every planned maintenance visit at contract signature, not when the calendar has space. A 12-month service contract signed in January should have a maintenance visit booked in October or November, giving the client the inspection before the end of the contract year and giving the installer enough lead time to fit it into their schedule without pressure. The visit date should be confirmed in writing to the client at the start of the contract.

Documentation from a maintenance visit needs to be formal enough to stand as evidence of compliance with BS7671 testing requirements and the terms of the service agreement. For each charge point inspected: the circuit test results, the equipment function test outcome, the firmware version confirmed, any defects found and the action taken, and the engineer's sign-off. That documentation goes to the client within 24 to 48 hours of the visit, not weeks later when the invoice arrives.

Maintenance visits are also the right moment to identify upgrade opportunities. A charge point installed three years ago may be approaching end of manufacturer support, or the client's parking usage may have changed in a way that justifies adding capacity. A service engineer on-site with a documented record of each unit's age and condition is well-placed to raise those conversations with the client's facilities or operations contact. That conversation is the natural origin of the next installation job.

Billing for Ongoing Service - Structure, Timing, and Call-Out Invoices

The revenue model for commercial EV charge point service work is fundamentally different from installation billing. An installation job has a defined scope, a clear completion point, and a final invoice. A service contract runs for 12 months with a recurring fee, periodic call-out charges that may or may not arise, and parts invoices that are unpredictable in timing and value.

Annual service contract fees should be invoiced at contract signature, not monthly. Monthly billing for a £240-per-year contract generates 12 invoice transactions for £20 each, creating administrative overhead on both sides and a collection risk if a client changes bank details or payment approvals mid-year. A single annual invoice at the start of the contract term - with a clear breakdown of what it covers - is cleaner, reduces debtor days risk, and prompts the client to formally acknowledge the scope they have agreed to.

Call-out invoices, for visits outside the included allowance, need to be raised promptly - ideally within 24 hours of the visit. A call-out invoice raised three weeks after the engineer visited leaves the client uncertain whether the visit will be charged, and gives them time to question whether it should have been covered under the contract. A same-day or next-day invoice, accompanied by the fault log for that visit, is harder to dispute and faster to pay.

Parts invoicing adds a third billing stream to manage. When a faulty component is identified on a call-out or during a maintenance visit, the parts cost needs to be quoted to the client before ordering, confirmed in writing, and invoiced separately from the call-out charge. The parts invoice should reference the call-out job number, the charge point serial number, and the fault that required the replacement. Without that reference chain, parts invoices become the most contested items on any service account.

Managing the Service Operation in Zigaflow

As a service contract portfolio grows, the operational administration - scheduling maintenance visits, logging faults, raising call-out invoices, tracking parts orders - becomes the constraint on how many contracts can be run profitably. Zigaflow supports each of those streams in one system.

Annual service contracts can be set up as recurring jobs with scheduled tasks for the planned maintenance visits, keeping the visit calendar visible against each client account. Fault call-outs are raised as separate jobs linked to the same client, with the fault log captured in the job record and the call-out invoice raised directly from the job when the engineer marks the work complete. Parts procurement runs through purchase orders raised against the job, so the parts cost is matched to the client account before the parts invoice arrives from the supplier.

The service history for each client's charge point estate - all faults, all visits, all parts replaced - lives in the job record rather than across spreadsheets, email threads, and phone notes. When a client asks why a particular charger has had three faults in six months, the answer is in the system.

Building a Service Contract Book Alongside Installations

The commercial case for building a service contract book alongside installation revenue is straightforward. Installation jobs are episodic: a site either has charge points or it does not. Service contracts are recurring, predictable, and - if priced correctly - generate positive margin on every visit that does not require parts replacement. A 20-site service contract book at £500 per site per year is £10,000 in predictable annual revenue before a single new installation is quoted.

The operational challenge is keeping the service side of the business from running on goodwill and memory when the installation pipeline fills up. Fault logs, maintenance visit records, and call-out invoices need to be as systematic when the team is busy as when it is quiet. The installers who build that discipline early, before the service book grows large enough to cause problems, are the ones whose service contracts renew without friction - and whose clients call them first when the next installation opportunity arises.