Every tradesperson knows the call. A week after the job: "you were never here", or its cousin, "after you left, it leaked". You remember the visit; you cannot prove it. For a company with a dispatcher and a legal department this is a process. For a solo plumber, electrician or cleaner it is your word against the client's, and the client is the one who pays. The fix is a paper trail that takes seconds to create: a check-in, a photo, a signature.
The three artifacts
1. A geo check-in. One tap on arrival records the time and the location. It is a small, dry fact: "on site at 09:04, coordinates match the address within a dozen meters". It does not prove the quality of the work, but it kills the most common dispute of all, the one about whether the visit happened.
2. A photo of the result. Taken before you leave, while the light is on and the floor is dry. The photo answers "what state did you leave it in" better than any memory, and a month later it is the only evidence that the scratch on the cabinet was already there.
3. A signature on the screen. The client signs on your phone: work seen and accepted at this time. It is the classic proof of delivery that large companies pay subscriptions for, compressed into ten seconds. A signature does not make later complaints impossible; it makes "I never accepted this" impossible.
Where disputes actually come from
Mostly not from malice. The client genuinely does not remember which Tuesday you came, whether the noise started before or after your visit, what you said about the old valve. Memory is the weakest witness in the room. The three artifacts replace both memories, yours and theirs, with timestamps, and most arguments dissolve at the moment you read the record aloud.
The month-end bonus
The same records that settle disputes also write your reports. A cleaning company sends its corporate client a CSV of all visits with times and durations, attached to the invoice, instead of reconstructing the month from chat history. A maintenance contractor exports the quarter per site, with photos. The paper trail that protects you turns out to be the paperwork you owed anyway.
What to use
A paper diary fails at photos and gets lost with the van. The big field-service platforms (Jobber, Workiz and friends) do all of this well and cost 30-80 EUR per user per month, alongside dispatch modules a one-person business will never open. The gap between "notebook and WhatsApp" and "enterprise subscription" is exactly where a solo tradesperson lives.
We are building Fyntoo Field for that gap: a free app with the day's jobs on a map, one-tap navigation, geo check-in, result photos and the client's signature. It is in testing now. Meanwhile the habits cost nothing and work with any tools: check in when you arrive, photograph before you leave, get the signature while you are both looking at the finished work. One settled dispute pays for the discipline many times over.