How To Track Job Costs And Purchase Orders On Trades Jobs

Quick Answer

Raise purchase orders from the job when you need supplier materials, log parts and receipts against the same job, and compare labour plus materials to what you quoted. Review margins weekly on a few finished jobs. Stop storing costs only in the bank feed or a carrier bag of receipts. Honest job costs make the next quote sharper.

Introduction

Many firms know turnover and still cannot say which jobs made money. Materials hit the company card, a merchant account gets paid at month end, and labour hours live in someone's head. By the time accounts tidy it up, the next similar job is already underquoted.

Job cost tracking is not enterprise bureaucracy. It is attaching spend and time to the work so you can see profit while the job is still warm. Purchase orders are how you tell suppliers what you need without losing the link to that site.

Related habits: track time and materials on jobs, quoting, and suppliers coverage on the features page.

Why Job Costs And POs Matter

Margin truth. A busy week can still be a poor week if materials ate the job.

Fewer lost costs. Parts bought "for the van" that belonged to a customer never get billed.

Cleaner supplier talk. A PO with job reference beats a vague phone order when deliveries go wrong.

Better pricing. Next quote uses real numbers from the last three similar jobs, not hope.

Purchase Orders In Plain English

A purchase order is your instruction to a supplier: what you want, for which job, at what expected price, and where to deliver. It does not replace the supplier invoice. It creates a trail before the goods arrive.

Use POs when materials are ordered specifically for a job, values are material, or multiple people can spend. Skip heavy PO process for a £8 consumable from stock if that slows the day, but still log the cost to the job when it matters for margin.

What To Capture On Each Job

1. Labour. Hours or day rates actually used, not only what you hoped.
2. Materials. Parts from stock and special orders, with cost if you know it.
3. Supplier POs. Linked to the job and closed out when goods arrive.
4. Receipts. Photos or uploads against the job the same day.
5. Extras. Customer-approved variations with cost and sell price.
6. Subcontractor charges. If someone else did part of the work.

Quick checks: profit calculator and material markup calculator for pricing sense-checks. Receipt capture habits sit with AI OCR on features, but the discipline is still "attach it to the job today."

Common Mistakes

• Ordering materials with no job reference
• One merchant account balance and no job split
• Quoting without looking at the last similar job's real cost
• Logging sell price but never cost price
• PO raised, goods arrive, nobody marks them received on the job
• Engineers buying on personal cards with repayment weeks later
• Ignoring travel and wasted visits in true job cost
• Waiting until year end for the accountant to invent margins

Simple Process Checklist

1. Open or confirm the job before you order special materials
2. Raise the PO from that job with supplier, lines, and delivery notes
3. When goods arrive, check against the PO and log exceptions
4. Photograph receipts and attach them the same day
5. Log labour as work happens, not on Friday from memory
6. Before final invoice, scan costs vs quote for missed billables
7. After payment, glance at margin: keep, tweak price, or change process
8. Feed patterns into your next quote template

Margins Without Spreadsheet Hell

You do not need a full ERP. You need enough cost on the job to answer: did this bathroom make money? Weekly, pick five completed jobs and compare quoted labour and materials to actuals. Patterns appear fast: under-estimated first fix, forgotten fixings, optimistic hours.

VAT and invoice clarity still matter for what the customer pays, but margin is about your cost versus your sell. See VAT on quotes and invoices for customer-facing totals.

If costs live in Xero only, you still want the job link so field and office speak the same language. Xero connection guide: connect job software to Xero.

How Software Helps

Carrier-bag accounting fails because receipts and jobs never meet. Software helps when POs, costs, and labour sit on the same record as the quote and invoice.

Total Tradesmen supports supplier directory, purchase orders from a job, receipt upload, and job cost tracking so parts, materials, and time stay tied to the work. AI supplier search and receipt reading speed entry, but the win is one place to see whether the job was worth it.

Benefits

• Fewer unbilled materials
• Clearer conversations with suppliers when deliveries fail
• Quotes based on evidence, not optimism
• Less month-end detective work
• Ability to drop or reprice chronically bad job types

FAQs

Do small one-van firms need POs?

Use a light version: job reference on every order and costs logged on the job. Formal POs matter more as soon as more than one person can spend.

What if I do not know exact cost until the supplier invoices?

Log an estimate on the PO, then update when the invoice arrives. Waiting for perfect numbers is how costs stay invisible.

Should every screw be tracked?

No. Track what moves margin: major parts, special orders, and labour. Use a small consumables allowance if that keeps the team moving.

How does this link to deposits?

Deposits protect cash when you order materials. Costs and POs tell you whether the job still profits after those materials land. See deposits and staged payments.

Conclusion

Job costs and purchase orders work when every meaningful spend is tied to the job before the memory fades. Raise POs from the work, attach receipts, log labour, and review margins on finished jobs. That is how you stop guessing and start pricing like a business.