Proof of delivery in field services: what a job record needs to show
Why it is different in field services
Proof of delivery is familiar from parcels: a signature at the door. Field work needs more. An installation, survey, repair or upgrade can be finished without anyone who matters being able to tell whether it meets the requirement. The approver is usually not on site, the work may pass through several subcontractors, and the invoice is raised days or weeks later. Proof of delivery is what lets the accountable business stand behind the work to its own customer, and what lets the people who did it get paid.
What the record should contain
- The requirement: scope, site details, acceptance criteria, agreed rates and who may approve changes, set before the job.
- The evidence: photographs, test results, readings, serial numbers and notes, each captured against the check it demonstrates.
- Provenance: when and where each item was captured and by whom.
- Changes: what changed, its effect on time or price, and who authorised it. Evidence of extra work is not the same as permission to charge for it.
- Exceptions: access failures and missing prerequisites, recorded when they happen.
- The decision: accepted, or a specific exception raised, by an authorised reviewer.
What makes it trustworthy
- Contemporaneous: captured as the work happens, not reconstructed at invoice time.
- Tamper-evident: corrections are logged, never overwritten.
- Connected: evidence, changes and the decision sit on the same job record as the commercial terms.
- Proportionate: only what the acceptance criteria need, with sensible retention.
- Separated: each customer’s records are visible only to the people entitled to see them.
Common failures
- Photos in personal phones and messaging apps, without context.
- Sign-off on paper, scanned days later or lost.
- Extra work agreed by phone with no record of the approval.
- Acceptance criteria that exist only in the end customer’s contract.
- A completion status in the ticketing system with nothing behind it.
Each of these turns into one of the five costs of unproven work: a revisit, an unattributable fault, a reconstructed invoice or a payment waiting for a decision.
How to set it up
- Agree the acceptance criteria with your customer and translate them into checks for each job type.
- Build those checks into a runbook the engineer follows on site.
- Capture evidence against each check, with time and location recorded automatically.
- Route the record to an authorised reviewer who accepts or raises a specific exception.
- Raise the invoice from the accepted record.
How FortyFive helps
FortyFive builds proof of delivery into the job. Runbooks carry the acceptance criteria, engineers capture evidence on their phone against each check, changes are approved in context, and the reviewer accepts against the criteria. The result is a tamper-evident delivery record you can share with your customer and invoice from. See how a job moves through FortyFive.
Sources
- FortyFive, The cost of unproven work, white paper, 2026: section 4, “The delivery record”.
Last updated · FortyFive
Frequently asked questions
How is this different from proof of delivery in logistics?
In logistics, proof of delivery usually means a signature or photo showing goods arrived. In field services the question is harder: not whether someone arrived, but whether the work meets the agreed requirement and can be approved for payment.
Are photos enough?
A photograph is useful only if it answers a relevant question. Proof of delivery ties photos, test results and readings to the acceptance criteria they demonstrate, with time, location and the person who captured them.
What does tamper-evident mean?
That any change to the record is visible. Corrections are logged alongside the original rather than overwriting it, so the record can be relied on later without pretending mistakes never happen.
Does more evidence mean better proof?
No. Proportionate evidence is better: enough to support a sound decision, without creating administration for the team doing the work or collecting personal data that is not needed.
Who should define what proof is needed?
The business accountable to the customer, before the job starts, usually based on the end customer's own acceptance criteria. The delivery team should see those requirements before accepting the work.
Related terms
The cost of unproven work
The cost of unproven work is the time, money and working capital lost when field work is completed but cannot readily be approved and paid, because the record of what was done is missing, incomplete or disconnected from what was agreed.
The done-to-paid gap
The done-to-paid gap is the elapsed time between field work being completed and payment for it being received. It runs from completion through evidence, acceptance and invoicing to settlement.
Field service orchestration
Field service orchestration is the coordination of field work across all the businesses involved in delivering it (the accountable business, its partners and subcontractors, and the engineers on site) so that requirements, people, evidence and payment move together on one record.
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