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Job costing software: knowing which jobs made money and which did not

Job costing software assigns labour, materials and overhead to each job so margin is visible per job rather than per month. What it must capture, and how to job cost properly before buying anything.

How-toJ

Job costing software tracks the cost of each job separately — labour hours, materials, subcontractors, plant and a share of overhead — so you can see the margin on job 412 rather than only the margin for September. Any business quoting work priced per project needs this: without it, profitable and loss-making jobs average into one number that looks acceptable while specific customers or job types quietly lose money.

What job costing software has to capture

  • Labour hours per job, per person, at their actual cost rather than a blended rate.
  • Materials issued to the job, including what was returned unused.
  • Subcontractor invoices matched to the job before payment, not after.
  • Plant and equipment time, charged internally so the machine pays for itself.
  • Overhead allocation on a stated basis — labour hours, revenue or a fixed percentage.
  • The quote or estimate, so committed and actual cost sit side by side.
  • Variations and extras as their own lines, because that is where disputes and lost margin live.

Estimate versus actual is the whole point

A job costing report that shows only actual cost tells you what happened; one that shows estimate against actual tells you why. Break the comparison down by cost type: labour overrun means the estimate assumed too few hours or the crew was slower, material overrun means waste or price movement, and repeated subcontractor overruns usually mean the scope handed over was vague. The pattern across jobs is what improves the next estimate, and improving estimates is where the money is.

Capture labour daily. Hours reconstructed at the end of a job from memory are wrong in a consistent direction — always too few — which quietly flatters margin on the jobs that actually went badly.

Job costing before you buy software

  1. Give every job a code and use it on timesheets, purchase orders and supplier invoices.
  2. Record hours daily per job, even roughly; consistency beats precision.
  3. Post materials to the job when they are issued, not when the invoice arrives weeks later.
  4. Choose one overhead basis and keep it — changing basis mid-year makes years incomparable.
  5. Review estimate against actual for every completed job, and write down one lesson for the next estimate.
  6. Look at margin by job type and by customer, not just by job — the loss pattern is usually a category.

Ettex Sheets carries this at small and mid scale: a jobs tab with quote and status, a time tab posted daily, a materials tab keyed by job code, and a margin view that recalculates as costs land. The discipline it enforces — one job code used everywhere — is the same thing dedicated systems require, so nothing is wasted if you outgrow it.

Frequently asked

What is the difference between job costing and process costing?

Job costing tracks cost per identifiable job or project, suited to construction, engineering and agency work. Process costing averages cost across units in continuous production, suited to manufacturing runs.

How should overhead be allocated to jobs?

By a basis that reflects what drives overhead — usually labour hours for labour-intensive work. The important thing is stating the basis and keeping it consistent so comparisons hold.

Can job costing be done in a spreadsheet?

Yes, up to a few hundred jobs a year, provided job codes are used consistently on timesheets and purchases. The failure mode is codes missing on supplier invoices, not the spreadsheet itself.

MI
Written by Maria I.

Part of the Ettex team — writing about product, engineering and the future of work.

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