Case study · Finance & admin
The expense report that files itself.
This is one of our own builds — a working tool, not a concept. It handles monthly expense reports for a travelling sales professional at an international company, and it shows the pattern we bring to most first projects: find one repeated task, fit the tool to the format that already exists, keep a person in control, and measure the result. Details are anonymized; the numbers are real.
The pain: one evening a month, every month
The workflow will sound familiar. A month of travel produces a pile of receipts — parking, meals, flights, hotel folios, some paper, some emailed PDFs, in more than one currency. Filing the report meant photographing each receipt, typing merchant, date, and amount into the company's Excel template, categorizing every line, assembling a PDF of receipts in the same order as the spreadsheet rows, and emailing the bundle to finance. Thirty to forty minutes of careful, error-prone clerical work — done by someone whose actual job is selling.
There was also a paid expense app in the picture. It captured receipts well enough, but finance didn't want its export — they wanted their own template, so the re-typing survived the subscription.
What we built
A small, self-hosted tool with one job. Receipt photos get dropped into a shared folder from a phone. An AI vision model reads each one — merchant, date, amount, currency, category — and a review screen shows every extracted line next to its receipt image. The person checks the lines, fixes anything the model got wrong, and approves. The tool then fills the company's existing Excel template, assembles the receipt PDF in matching row order, and drafts the email to finance.
Three design decisions did most of the work:
- Fit the format that exists. Finance kept receiving the exact template they'd always used. Nobody downstream had to change anything, so there was no adoption battle.
- Keep a human on approval. The model reads; the person approves. OCR mistakes get caught in a ten-second scan instead of surfacing in an audit.
- Own it, don't rent it. It runs on hardware the owner already had. The paid expense app was cancelled.
The result
About 25 minutes saved per report — the job went from an evening chore to drop, review, send. The subscription line went to $0/month. Error rate went down, not up, because every line is verified against the receipt image on one screen instead of being re-typed from a stack. And the tool needs no vendor to keep running: it's documented, small, and owned.
Why this pattern generalizes
Nothing about this is specific to expenses. The shape — messy documents in, a person approving in the middle, a clean record in your existing format out — is the same one we use for receiving discrepancies, damage claims, field compliance records, and invoice intake. It's also why we tell clients to start small: a tool like this is scoped in days, built in weeks, and pays for itself on a schedule you can see. That logic is the heart of measuring AI ROI in the first 90 days.
If you'd rather explore the category first, our guide to smart bookkeeping with AI covers what to automate and what to keep human.
Have a report your team hand-builds every month?
Tell us which one. We'll scope the same pattern around your format, your approval rules, and your systems — and give you an honest read on what it would save.