Definitions
What is proof of service software?
Proof of service software keeps a record that each scheduled visit or job was answered: a photo, the time a server received it, and often a location. It is built for recurring work, where someone who was not there later asks whether the visit happened. LockProof, field work verification software for recurring visits, is one example: the worker answers a texted link with a live photo, and the record carries a server-set time and a SHA-256 fingerprint, plus location when the worker shares it.
What proof of service software records
The record starts before anyone takes a picture. For a job on your schedule, LockProof opens the record on the server before the worker opens the link, then sends the link by text, WhatsApp or email.
- The link opens the phone’s live camera. Gallery uploads are blocked, so an old photo can’t be attached.
- The photo’s time comes from the server, on arrival. On time or late is worked out from that time against when the check went out.
- A SHA-256 fingerprint covers the image and the server-set time, plus the coordinates when the worker shares location, so a later change to the record is detectable.
- A check with no photo once its window closes counts as missed, and the manager on record gets an email unless the company turns those alerts off.
- The office can send an owner or a client a proof link: a single record that opens from any browser, without signing in, for seven days.
The LockProof glossary defines server-set time, fingerprint and proof link, and the help center walks through each step.
What it does not prove
A photo does not prove the work was done well. It shows the scene the camera saw when the worker took it, and nothing outside the frame.
Location is conditional. The phone asks for it on submission and the coordinates are saved only when the worker shares them. A company can require a reading before a worker can submit, but that rule checks that a reading exists, not where it came from. An optional proximity flag, for sites with coordinates set, compares it with the site and marks a far-off photo for the office; it never rejects one.
The time is the server’s, not the camera’s. It is recorded on submission. The phone’s own clock is kept as information only.
A fingerprint shows the record has not changed since it was sealed. It does not show the scene was genuine, and a record does not decide a dispute. It gives whoever reviews it the capture, the time and the history to weigh.
How it differs from a photo app, a time clock and a job suite
A photo app is built for taking, sorting and sharing pictures of a job. A time clock records the hours a worker was on the clock, usually for payroll. A job suite runs scheduling, quotes, dispatch and invoicing. Proof of service software has a narrower job: it asks for a photo on a schedule and keeps what came back as a dated record a client can open.
LockProof is not a time clock and does not run payroll or invoicing. It can sit beside the job suite a team already uses. If you run a cleaning company, see proof of service for commercial cleaning; for products side by side, see the roundup of software to prove field work was done.
Also called field work verification software
The two names describe the same category. Field work verification software is the name LockProof uses for itself. Proof of service software is a name buyers use too.
Questions, as of November 5, 2026
Is proof of service software the same as EVV?
No. EVV, electronic visit verification, is the system that state Medicaid programs use to confirm in-home personal care and home health visits. LockProof is not an EVV system. Where an agency runs one, LockProof’s photos sit in a separate file next to it.
Does proof of service software need an app?
Some products use an app the crew installs. LockProof uses a link instead: the worker taps it, the phone’s browser opens the camera, and there is nothing to install and no sign-up.
Does a proof of service record show where the worker was?
It shows the location the worker shared, recorded on submission, when they shared it. LockProof compares that location with the site only when the optional proximity flag is on and the site’s coordinates are set, and that flag never blocks a submission.
Who uses proof of service software?
Companies whose crews do recurring work at sites the client cannot watch in person: commercial cleaning routes, security patrols, property maintenance, snow removal, field service calls and home care visits.