The short answer: Proof of work for field jobs is tamper-evident evidence that work was actually completed — captured at the moment of work, not after. It includes GPS-stamped photos, timestamps, compass direction, and a digital signature. The key difference from regular photos? The proof is locked after capture and can't be edited, so both sides have a record they can trust.
Why "proof" matters more than "photos"
Anyone can take a photo. But a photo alone doesn't prove:
- Where it was taken (could be anywhere)
- When it was taken (could be last year)
- What direction the worker was facing (could be a different part of the site)
- Whether it's been edited (filters, crops, even AI-generated images)
Proof of work solves all of these problems by capturing metadata at the moment of work and locking it so it can't be changed.
The five components of field proof
1. GPS coordinates
Every photo is stamped with the exact latitude and longitude where it was taken. This proves the worker was at the job site — not at home, not at another location, not using an old photo.
2. Timestamp
The exact date and time of capture, locked at the moment the photo was taken. This proves when the work happened, not just that it happened at some point.
3. Compass direction
The device's compass bearing at the moment of capture. This is especially useful for multi-location jobs — you can see which direction the worker was facing, confirming they were looking at the right part of the site.
4. Digital signature
The worker signs on their phone at the moment of completion. This is captured on-site, not added later. The signature confirms the worker is attesting that the work shown in the photos was done by them.
5. Tamper-proof lock
Once submitted, the entire record — photos, metadata, signature — is locked. It can't be edited, replaced, or deleted. This is what makes it "proof" rather than just "documentation."
How proof of work prevents disputes
Disputes happen when two parties disagree about what happened. With proof of work:
- There's no "he said, she said." Both sides see the same record.
- The evidence can't be fabricated. GPS + timestamp + compass + signature make fraud extremely difficult.
- The record is locked. Neither party can edit it after the fact.
When you can point to a tamper-evident record that both parties agreed to at the moment of work, disputes end before they start.
Proof of work vs. other approaches
Photos in WhatsApp
Easy to send, but no GPS stamp, no timestamp lock, no compass, no signature, and easily editable. Good for communication, bad for proof.
Checklists in spreadsheets
Self-reported data. The worker says they did the work, but there's no independent verification. Easy to mark "complete" without actually doing anything.
Photo apps (like CompanyCam)
Good for organizing photos, but not designed for subcontractor workflows. No job assignment, no tamper-evident locking, no signature capture. Built for your own crew, not for vendors.
Proof-of-work platforms (like Fieclo)
Combines job assignment, tamper-evident capture, and shared records in one tool. Built specifically for the subcontractor workflow — assign, prove, both sides keep the record.
When you need proof of work
You need proof of work when:
- You subcontract jobs to outside vendors and need to verify completion
- You manage field crews and need to know what was done without visiting every site
- You have customers who might dispute whether work was completed
- You pay based on completion and need evidence before releasing payment
- You're in a regulated industry where documentation is required
Getting started
Proof of work doesn't require expensive enterprise software. Fieclo starts free with 5 jobs — enough to try the workflow on a real job. The worker captures proof on their phone, you both see the same record, and the dispute cycle breaks.