Proof of completion for field service
A completion sign-off is not proof the job got done
A sign-off is only as good as the proof behind it
Between 2015 and 2021, a supplier called DRI Relays sold the Defense Department electrical relays and sockets it certified as meeting military specifications. The certification was the product: a signed statement that the required tests had been run and passed. They had not been. The parts shipped, the paperwork said tested, and the testing simply never happened. DRI’s parent company later disclosed the gap, and in April 2025 DRI agreed to pay $15.7 million to settle False Claims Act allegations. Strip away the defense contract and the dollar figure and what is left is ordinary: a sign-off said the work was done, and the proof behind the sign-off did not exist. Reported by the U.S. Department of Justice and Constantine Cannon.
A sign-off is a claim about work, not the work itself. The gap between the two does not care whether the job is a military-grade relay or a Tuesday service call. In field service the claim usually arrives as a tapped button. The technician marks the work order complete, and the dispatcher, the customer, and the adjuster downstream are all trusting the tap.
The button records a claim, not the work
Here is the mental model most field-service software runs on: a work order marked done means the job got done. It holds right up until someone disputes it, and then it comes apart in one step. The button does not record the work. It records that a person pressed a button. Nothing in a checkbox ties the claim to the site it was made about, the time the work was actually finished, or the condition it was left in. An e-signature does not close the gap; it adds a name to the claim. Proof has to come from the job, not from the record of someone asserting the job is finished.
How the record gets made
The alternative is to capture the finished job at the moment it is finished, in a way that is boring to produce and hard to change after the fact. Four steps, no app for the technician, and nothing typed in later.
- Dispatch the job. The technician gets a text with a link. No app to install, no login.
- The link opens the camera. Gallery uploads are blocked, so the photo of the finished work is taken on site, not pulled from a camera roll.
- The record seals itself. A server-set time attaches on submission, with GPS when the worker shares location, and a SHA-256 fingerprint makes any later change detectable.
- You see it, and can share it. The completed job lands on your dashboard, marked done, late, or missed, and shares as one signed link when a customer asks.
What a completed job carries
- A live photo of the finished work, captured through the link (gallery blocked)
- GPS recorded on submission when the worker shares location, flagged for you if it lands beyond a set distance from the site
- A server-set timestamp the technician cannot change
- A SHA-256 chain of custody on every record
- A dashboard that marks each job done, late, or missed
- An Evidence Vault you can search by site, technician, or date
- A shareable signed proof link that expires after 7 days
- No technician app or login, in English and Spanish
Sign-off vs. proof
The two look alike in a dashboard. They are not the same the day a customer pushes back.
| What the record carries | LockProof | A completion sign-off |
|---|---|---|
| Shows the finished work | A live photo | A checkbox |
| Tied to the site | GPS when shared | No |
| Time you can trust | Server-set | Typed or device time |
| A later edit is detectable | SHA-256 chain of custody | No |
| Filed and searchable | Evidence Vault | In the work order |
| Ready to share in a dispute | One signed link | The sign-off only |
See a finished example in a sample verified record, or how it fits field service teams. And if a customer ever disputes a job, the proof is already filed, dispute-ready.
Common questions
What counts as proof of completion for field service?
Proof of completion is a record made at the job, not a claim entered afterward. It carries the finished work as a live photo and a server-set time the technician cannot change, plus the GPS where it was taken when the technician shares location. A work order marked done is a claim; a captured, sealed record is the evidence behind it.
How do you prove a technician was actually at the job site?
When the technician shares location, the record carries the GPS reading recorded on submission. If you turn on site proximity, LockProof also saves how far that reading was from the site and flags it on your dashboard when it lands beyond a distance you set, so a photo taken two blocks away shows that distance. It is not a tracker running all day: one location tied to the finished job, not a trail of the technician's movements.
Can a completion photo or its timestamp be faked?
The link opens a live camera only, with gallery uploads blocked, so a photo from last week can't be attached. The time is set by the server, not the handset, and reminder timing is randomized. Every record carries a SHA-256 fingerprint, so any later edit stops matching and is detectable.
What do you show a customer who disputes the work?
One record: the live photo of the finished job, the server time, the full event history, and its GPS when the technician shares location, shared as a single signed link. The customer sees the work, and when — and where, when location was shared. The dispute moves from your word against theirs to a record that stands on its own.
Is a customer signature proof of completion?
A signature confirms the customer agrees the work looks done. That is a claim, not evidence of the work itself: it does not show the finished job, where it was, or when. Pair the sign-off with a captured record, a live photo with a server-set time and GPS when the worker shares location, so the signature rests on proof instead of standing in for it.