You finish the month with a full invoice ledger and a healthy bank balance. Work has been steady, the team has been busy, so the surprise when the accountant shows you the numbers and the profit is half what you expected is a genuine one.
This happens more than most field service business owners admit. The gap between what a job looks like on paper and what it actually costs to deliver persists across the industry precisely because it’s invisible until someone looks for it. Most businesses can tell you their turnover. Very few can tell you, with confidence, what they made on any individual job once all the real costs are counted.
Table of Contents:
- Revenue is not profit
- The true cost of an engineer in the field
- Overhead: the cost that never gets allocated
- Markup vs margin: the confusion that costs thousands
- The jobs you think are profitable but aren’t
- Rework is a costing problem, not just a quality problem
- What job costing actually makes possible
- How Fieldmotion supports job-level visibility
Revenue is not profit
The distinction sounds obvious until you look at how most field service businesses actually track performance. Revenue gets monitored closely: jobs booked, invoices sent, payments received. Cost is tracked at a business level through the P&L. What’s rarely tracked is profitability at the individual job level.
General accounting tells you whether the business as a whole is making money. Job costing tells you which jobs are making money and which are costing more than they should. Most businesses track the first. The second is where the real information lives, and the answer is often uncomfortable.
A business doing £800,000 in annual revenue with a 15% net margin is making £120,000 a year. But if some jobs are running at 25% margin and others are running at 5% or below, the average hides a significant opportunity. Finding and fixing the underperforming jobs is often worth more than chasing additional revenue.
The root cause is almost always the same: prices were set based on what seemed reasonable, or what the market appeared to accept, rather than on a clear calculation of what each job actually costs to deliver.
The true cost of an engineer in the field
Most field service businesses price labour using something close to the engineer’s wage. An engineer earning £35,000 per year works out to roughly £16-17 per hour. Add a margin and that becomes the labour component of the quote.
The problem is that £35,000 is not what that engineer costs the business.
On top of the base salary, an employer pays National Insurance contributions. From April 2025, the employer NI rate is 15% on earnings above £5,000 per year, up from 13.8% previously, and applying from a lower threshold than before. The combined effect of the rate increase and the lower threshold means that giving an engineer a 1% pay rise now costs an employer more than 10% more in total employment costs once NI is factored in. For a £35,000 salary, employer NI alone adds approximately £4,500.
Then there’s the mandatory workplace pension contribution, at least 3% of qualifying earnings. Holiday entitlement runs to 5.6 weeks per year, meaning the engineer is paid for roughly 47 working weeks of actual work rather than 52. PPE, tools, work clothing, and training are further costs that belong to deploying that engineer on a job.
Add those together and the true employment cost of a £35,000 engineer is closer to £42,000-44,000 per year. Price the labour component at the wage, and you’re undercharging by 20-25% on every job before you’ve accounted for anything else.
This isn’t a small rounding error. On a business doing 2,000 labour hours per year, the gap between pricing at wage cost and pricing at true employment cost represents tens of thousands of pounds of unrecovered cost annually.
Fieldmotion Brochure
See how Fieldmotion helps field service teams manage jobs, schedule staff, create invoices, and communicate with customers — all from one easy-to-use system.
Overhead: the cost that never gets allocated
Every field service business carries overhead costs that exist regardless of whether any jobs are being done: van payments and running costs, insurance, tools and equipment, software, accounting, admin time, marketing, and the owner’s own time when they’re not directly delivering work.
These costs don’t disappear when jobs are priced cheaply. They get paid from whatever is left over after the job is invoiced. When overhead isn’t allocated to individual jobs, it accumulates invisibly until the year-end accounts reveal the problem.
The calculation isn’t complex. Take all the fixed and semi-fixed costs of running the business for a year and divide them by the number of billable hours available. A small field service team might carry £80,000-£100,000 in annual overhead before accounting for labour. If that business has 3,000 billable hours available across its engineers, the overhead cost per billable hour is £27-33.
That figure needs to be built into every job price. If it isn’t, those costs are being subsidised by margin that was supposed to be profit.
There’s a further complication: not all hours are billable. Engineers travel to jobs, complete paperwork, attend tool checks, deal with queries, and spend time in transit between sites. Industry research consistently finds that a significant portion of a field service technician’s working day is absorbed by non-billable tasks, with paperwork and administration among the most frequently cited.
The consequence is a gap between theoretical capacity and actual billable hours that most businesses have never measured. As one contractor put it when working through this with an accountant: “I can calculate labour. I know labour. I know materials. Beyond that, I really don’t know how much it takes to do a job.” That gap, between what appears to cost and what actually costs, is precisely what job costing is designed to close.
If an engineer works a 40-hour week but only 28 hours are billable, the overhead cost per actual billable hour is higher than the simple annual calculation suggests. Businesses that don’t account for this gap are pricing their labour cost on the assumption of full utilisation, then wondering why the margins aren’t there.
Markup vs margin: the confusion that costs thousands
This misunderstanding sits at the root of a lot of unexplained margin shortfalls in field service pricing, and it compounds silently across every job a business prices.
Markup and margin both express the relationship between cost and price, but they mean different things.
A 20% markup on a £1,000 job means adding £200, giving a price of £1,200. That looks like 20% profit. But the actual margin, profit as a percentage of the sale price, is £200 divided by £1,200, which is 16.7%.
The difference grows with every job. On a £10,000 contract priced at 20% markup, the business believes it’s making £2,000 profit. It’s actually making £1,667. On a £100,000 contract, the gap is £3,333.
Businesses that have been pricing on markup for years while believing they’re achieving target margin will consistently find their actual profitability lower than expected. As one experienced building contractor put it plainly in a widely shared guide for trades businesses: “If you’re working in markup, your numbers are all getting skewed and missed. You think you’ve added 20% on, but you haven’t. There’s a 5K difference there just on one job alone.”
Working in margin rather than markup removes that distortion. Set a target margin for each job type, calculate the required sale price from the cost base, and measure actual margin on completion against the projection.
The jobs you think are profitable but aren’t
Even when a business has a reasonable handle on its costs, some job types consistently underperform. The pattern is usually invisible until you look at job-level data.
A commercial maintenance contract priced at a healthy margin on the assumption of straightforward quarterly visits may actually involve twice as many engineer hours as quoted because of access issues, equipment complexity, or repeat faults on particular assets. Without tracking actual time on site against estimated time, the margin erosion never surfaces until the contract comes up for renewal and someone looks at whether it’s worth keeping.
Similarly, some clients appear highly profitable based on invoice value but consume disproportionate amounts of administrative time, require frequent quoting revisions, have sites that are difficult to access, or generate a high volume of calls and queries between visits. None of those costs show up in the job record unless they’re being tracked.
Understanding your actual margin per job is the foundation for knowing which clients to prioritise, which job types to pursue, and where pricing needs to be adjusted. Without that data, pricing decisions are based on gut feel rather than evidence, and gut feel tends to favour the status quo.
Rework is a costing problem, not just a quality problem
Return visits and repeat callouts are usually treated as a service delivery issue: the engineer didn’t fix it correctly, the wrong parts were sent, the diagnosis was incomplete. All of that may be true. But the financial dimension gets less attention.
Each return visit has a cost: engineer time, fuel, the overhead allocation for those additional hours, and the scheduling overhead of rearranging other jobs to accommodate it. If the first-time fix rate is 80%, close to the industry average according to research cited across multiple field service benchmarks, then one in five jobs requires a second visit. On a team completing 1,000 jobs per year, that’s 200 additional visits that weren’t priced into the original job.
According to the Aquant 2024 Field Service Benchmark Report, a failed first visit can add 14 extra days and two additional visits to resolve a case. Lower-performing field service teams show avoidable dispatch rates of 24%, compared to just 3% for top performers.
For a business pricing jobs assuming a single visit, those return trips represent pure cost with no corresponding revenue. The margin on the original job absorbs them silently.
The practical implication is that first-time fix rate is not just a customer satisfaction metric. It’s a profitability metric. A 10 percentage point improvement in FTFR for a 50-engineer business, worked through a return-on-investment calculation, produces savings in the region of £300,000 per year from avoided repeat visits alone, before accounting for the additional revenue that the recovered engineer time makes possible.
What job costing actually makes possible
When a business tracks cost at the job level: actual labour hours versus estimated, parts used against parts quoted, travel time, return visits, and overhead allocation, several things become possible that weren’t before.
Pricing becomes grounded in evidence rather than optimism. If you’ve delivered 150 similar contracts over three years, you know the average time on site, the parts usage patterns, and the return visit frequency. That history produces a quote that reflects what the job will actually cost, not what you hope it will cost.
Client selection sharpens. Not all revenue is equally profitable, and job-level data shows which clients, sectors, or contract types generate healthy margins and which consistently underperform. That changes how you prioritise new business and how you approach renewals.
Tender conversations become factual. When a client pushes back on price or asks for additional scope within an existing rate, you can show precisely what the current work costs to deliver rather than defending a number you arrived at by feel.
Problems surface earlier. A job tracking ahead of its estimated cost in the first two days is a problem that can still be managed. The same job discovered at invoice stage has already eroded margin that can’t be recovered.
Resourcing decisions get easier to make. If job data shows that a particular type of work consistently takes 30% longer than estimated, the question becomes whether the estimating is wrong, the resourcing is wrong, or the job type isn’t viable at the current price. Without the data, that question never gets asked.
Capturing this consistently doesn’t require complex financial systems. It requires recording actual costs against jobs as a matter of routine and having a way to compare them against estimates.
How Fieldmotion supports job-level visibility
The data needed for job costing exists in every field service operation. The challenge is that it typically sits in separate places: labour hours recorded one way, parts tracked another, return visits not linked back to the original job, and admin time absorbed without being counted at all.
Fieldmotion captures the information that feeds job costing as part of normal operational workflow: engineer time logged against specific jobs, parts recorded against assets, return visits linked to original jobs, and invoicing tied directly to job completion. That data accumulates over time into a picture of actual job profitability that manual processes can’t produce.
For businesses tracking margin per job, that means comparing what a job was quoted to deliver against what it actually cost. Where those figures diverge consistently for a particular client, job type, or engineer, the data points to where pricing or processes need to change.
Book Your Free Demo
Discover how our job management software can streamline your operations, reduce paperwork, and keep your field teams on track.
FAQs
What is job costing in field service?
Job costing is the practice of tracking all costs associated with a specific job: labour, parts, travel, overhead allocation, and any return visits, then comparing the total against the revenue that job generated. It tells you the actual profit on individual jobs rather than just the overall profit of the business, which can look healthy while masking underperforming work.
Why do most field service businesses not do proper job costing?
Usually because the data required sits across multiple systems or isn’t captured digitally at all. Paper job sheets, verbal updates, and manual invoicing make it difficult to pull together a complete cost picture per job without significant manual effort. When everything is in one system, the data is available as a byproduct of normal work rather than requiring a separate process.
What costs do field service businesses most commonly miss when pricing jobs?
The most frequently missed are the labour burden on top of wages (employer National Insurance, pension, holiday pay), overhead allocation (van costs, insurance, tools, admin time), unbillable time (travel, quoting, paperwork), and the cost of return visits when first-time fix rates are below target. Markup vs margin confusion is also a common cause of margin being lower than expected.
What is the difference between markup and margin?
Markup is the amount added to the cost to arrive at a price, expressed as a percentage of the cost. Margin is the profit expressed as a percentage of the sale price. A 25% markup on a £100 cost gives a price of £125, but the margin is 20%, not 25%. Pricing consistently on markup while targeting a margin figure means the business is always slightly less profitable than it believes.
