Split Current: Reconciling Diesel and Electric Van Costs in One Fleet Ledger

A UK fleet no longer has one fuel ledger. It has two. Diesel vans still draw on fuel cards, bulk tanks and occasional forecourt receipts. Electric vans draw on depot chargers, home charging and public rapid units. The money leaves the business through different channels, on different cycles, with different evidence. If those streams are not reconciled together, the fleet’s cost per mile becomes a partial figure and drivers can be treated unevenly without anyone intending it.

Two energy streams, one cost question

The diesel side is familiar. A fuel card provider supplies transaction data, usually by card, vehicle and date, with litres, price per litre and VAT. The electric side is more fragmented. Depot charging may be metered by a charge-point management system, public rapid charging produces an app receipt or contactless record, and home charging may arrive as a monthly claim from the driver. The units are litres and kilowatt-hours, but the management question is the same: what did it cost to run this vehicle, and is that cost reasonable?

A workable mixed-energy ledger keeps litres and kWh separate in the raw data, then converts both to pence per mile for comparison. It should not force electricity into a litre equivalent unless that figure is needed for a specific report.

Allocating diesel-card costs

Start by tying every card transaction to a vehicle, not just a driver. Pool cards and unassigned cards create allocations that cannot be defended. Where a card is shared, record the vehicle on the transaction at the pump or through the provider’s mobile app. Reconcile the monthly card invoice to the transaction file and investigate outliers: a van that takes 90 litres when its tank is 70, a transaction in a county the vehicle did not visit, or two fills on the same day.

Diesel cost per mile should use the fuel actually consumed in the period, not simply the fuel bought. For most vans, purchases and consumption converge over a quarter. For a monthly report, note the difference and avoid over-interpreting a single fill.

Allocating charging costs

Depot charging is the cleanest electric stream when charge points are networked and tagged to vehicles or drivers. Use the charge-point report for kWh delivered, apply the site tariff and include VAT where recoverable. If the depot has a single sub-meter and no per-vehicle data, allocate by recorded charging sessions or by mileage until tagging improves.

Public rapid charging needs receipt discipline. Drivers should submit a photograph or app export showing date, location, kWh, total cost and VAT. The cost per kWh will often be higher than depot charging, and that is a legitimate operating cost, not a driver error. Reimburse or card-pay it promptly, but code it separately so management can see how much of the electric fleet’s cost comes from public charging.

Home charging and fair reimbursement

Home charging is the most sensitive area. A driver who plugs a company van into a domestic supply should not be out of pocket, but the business should not pay more than the energy used. Use a clear written policy: either an approved pence-per-mile reimbursement rate for home-charged miles, or a kWh calculation based on charger data or a certified meter. Keep the evidence for each claim.

Treat home-charging payments as a reimbursement under your own policy and take accountancy advice on VAT. Do not assume that input VAT can be recovered in the same way as a forecourt diesel receipt. The priority is consistency: two drivers on the same scheme should not receive materially different treatment because one has a smart charger and the other submits a manual claim.

A monthly mixed-energy reconciliation

A repeatable calendar matters more than a complex spreadsheet. Set a cut-off on the second working day of the month. Extract the diesel card file, the depot charge-point report, public charging claims and home-charging claims. Match each line to a vehicle and a cost centre. Validate odometer or mileage data from telematics or manual logs. Calculate diesel pence per mile and electric pence per mile for each vehicle. Produce an exception report for missing receipts, implausible kWh, duplicate claims and vehicles with no energy cost in the period. Approve the total and post it to the fleet cost centre.

Give one person ownership of the reconciliation and one person the right to challenge it. A transport manager can review operational exceptions; a finance officer can review VAT and coding. The process should take hours, not weeks, once the templates are set.

Making cost per mile comparable

Diesel and electric vans should be compared by duty cycle, not by blanket averages. A urban electric van doing 40 miles a day on depot charging will look very different from a diesel panel van doing 250 miles a week on motorways. Report cost per mile in bands: depot-charged EV, public-charged EV, diesel urban, diesel long-haul. That gives the fleet manager a fair comparison without pretending the vehicles are interchangeable.

In 2026, the mixed ledger is normal. The risk is not that electricity is more complicated than diesel; it is that the two are reconciled separately and never meet. A monthly process that brings both streams into one report keeps drivers fairly paid, keeps VAT and receipts in order, and gives the fleet a cost per mile it can actually use.