Why per-job margin beats the monthly P&L for hauliers

UK logistics moves a genuinely enormous volume of freight on the back of hundreds of thousands of HGVs and LCVs, and almost none of that fleet runs on software built for the person actually costing the job. Most haulage software was built as a transport-management system — a dashboard your accountant or your ops director bought — and its natural unit of truth is the month. Revenue in, costs out, margin at the bottom. That number can look perfectly fine while individual jobs are burning cash, because a monthly aggregate is exactly the wrong resolution to see it at.

How a monthly P&L hides a bad lane

Picture a small fleet running eight regular lanes. Six of them clear a healthy margin. Two of them — say, a long return-leg route with heavy dead-mileage, and a low-volume job priced years ago and never revisited — are quietly running at a loss, or close to it. Blended across the fleet and the month, the P&L still shows a positive number, because the six good lanes are subsidising the two bad ones without anyone deciding that on purpose. Nobody looking at the monthly total would know to go looking for the two lanes dragging it down. The number that would show it — cost and margin at the level of the individual job — was never calculated.

This isn't a hypothetical failure mode. It's the default state of any fleet costing at the monthly aggregate level rather than the job level, because the inputs that actually determine whether a job is profitable — dead miles, driver time, fuel burn for that specific route, whether the return leg carried a paying load or ran empty — vary job to job and lane to lane in ways a monthly total simply averages away.

What actually goes into a real per-job cost

Costing a single job properly means pricing in the things a monthly P&L can't see individually: the driver rate for the hours the job actually takes, the average speed and distance for that specific route, the fixed daily cost of running the vehicle whether or not it's earning, and — critically — the empty-running percentage, because a return leg with no paying load effectively doubles the cost the outbound leg has to absorb. Put those together and you get an effective cost per mile and per drop for that job specifically, not a fleet-wide average that happens to include it.

From there, margin becomes a real decision rather than a hope: a sell price at a margin floor — the absolute minimum acceptable, commonly treated as somewhere around 15% — and a margin target, the number you're actually pricing toward, often closer to 22%. A job quoted below the floor isn't marginal. It's a decision to lose money on that lane, made without anyone framing it that way.

The monthly P&L tells you whether the business survived the month. Per-job margin tells you which jobs paid for it.

Why this matters more as the fleet grows

A one-truck operator usually knows, instinctively, which jobs are worth doing — the margin is visible because the operator is also the driver, watching the fuel gauge and the clock in real time. That instinct doesn't scale. Once a fleet has several vehicles, several drivers, and a mix of contracted and spot work, the person setting the price is rarely the person running the route, and the feedback loop that used to be instant — "that job barely broke even" — gets buried inside a monthly total that averages it away with everything else.

Sub-contract-versus-in-house decisions run into the same blind spot. A lane that looks fine on a blended monthly basis might be quietly cheaper to sub out — or the opposite, a lane assumed too thin to bother with in-house might actually clear a healthy margin once dead miles and return-load economics are costed properly, job by job, rather than assumed.

The compliance layer sits on the same job object

Per-job costing isn't only a pricing exercise — the same job that needs a cost and a margin also needs to be legal to run in the first place, and the two questions are more connected than they look. A job priced without checking whether the vehicle and driver are actually clear to dispatch — O-licence financial standing, driver hours under the EU-derived or GB domestic regime, MOT and tax status, the walkaround check — is a job that might get costed perfectly and then held at the roadside anyway. Fleets that cost jobs properly tend to be the same fleets that check compliance properly, because both disciplines come from treating the individual job as the real unit of the business, rather than something that gets waved through on the strength of the monthly total.

What good per-job costing actually looks like

In practice, it means every job carries its own numbers before it's quoted, not after: distance and average speed for that specific route, driver cost for the hours it actually takes, a fixed daily cost allocated properly rather than ignored, and an honest empty-running percentage rather than an assumption that the return leg will "probably" carry something. It means a margin floor that's actually enforced — a job that prices below it gets flagged as a decision, not waved through because the customer's been on the books for years. And it means the fleet operator can answer, for any single job on the board, whether it made money — not just whether the fleet as a whole did.

The practical shift

None of this requires abandoning the monthly P&L — it's still the right view for cashflow, for the accountant, for the bank. What it requires is adding a second, finer-grained view underneath it: cost and margin computed per job, before the job is quoted, not reconstructed afterward from a spreadsheet nobody has time to build properly. Once that view exists, the two lanes dragging the fleet average down stop being invisible, and become a decision — renegotiate the rate, cut the dead miles, sub-contract it out, or walk away from the lane entirely.

The fleet that costs every job before it quotes it isn't doing more admin than the fleet that doesn't. It's just seeing the thing the monthly P&L was never built to show.