Fuel & Mileage Log with Reimbursement: Pay Drivers Right, Catch the Outliers

The problem this kills

Mileage and fuel reimbursement is one of those processes that quietly leaks money in both directions. Drivers email a manager a messy spreadsheet of trips, a fistful of crumpled fuel receipts, and an odometer reading nobody can verify. Someone in finance retypes it all, multiplies miles by a rate they hope is current, and cuts a payment — usually without ever noticing the trip that's twice as long as the route allows, the same gas receipt submitted in two different periods, or the truck that's suddenly burning fuel like it has a leak (or a side hustle).

The honest fixes are obvious and boring: capture the trips and receipts cleanly, compute the reimbursement the same way every time, flag the entries that don't add up, and make a manager actually look before money goes to payroll. That's not a feature your accounting package will grow for you, and it's not worth a five-figure fleet-software contract for a team of a dozen drivers. It's a small internal tool — and you can build it yourself, this afternoon, without being a developer.

What you'll build

A simple internal web app for your fleet. Drivers log each business trip (date, vehicle, start/end odometer or distance, purpose) and each fuel purchase, snapping a photo of the receipt. The tool computes each trip's mileage reimbursement from your current rate, and quietly runs sanity checks: it flags implausible mileage (distances that don't fit the time or the odometer), duplicate receipts (the same fuel purchase logged twice), and fuel-economy outliers — vehicles whose miles-per-gallon (or L/100km) suddenly drift, a classic early signal of misuse or a maintenance problem. At period close, a manager reviews each driver's log, sanity-checks the flagged items, and approves the period. Only then does the tool build an approved reimbursement batch and export it as a CSV in the exact columns your payroll or AP system imports. The AI does the math and raises the suspicions; a person makes the call.

What's inside the Implementation Plan

The downloadable plan is a step-by-step file you paste into an AI coding agent. It opens by interviewing you about your fleet — who your drivers and managers are, what vehicles you run, whether you track miles or kilometers, your current reimbursement rate and how it's set, exactly how trips and receipts reach you today, your real approval rules, and your messiest edge cases (personal-vehicle drivers, mixed personal/business trips, multi-day routes, fuel cards). It reads a short tailored spec back to you for a thumbs-up, then builds the tool around your fleet instead of a generic template. From there it walks the agent through the data model, the trip and fuel logging screens, receipt photo storage, the reimbursement and anomaly engine, the manager approval gate, and the payroll/AP CSV export. Every step ends with a ready-to-copy prompt.

The governance it includes (this is the point)

This isn't a toy. The plan builds in the controls a real finance and fleet function needs: login so only your team can use it, row-level security so drivers see only their own trips and managers see only their own team, a complete audit trail of every entry, edit, approval, and override (who, what, when, and why), a hard human-approval gate so no reimbursement reaches payroll until a manager approves the whole period, and duplicate guards so the same trip or receipt can't be processed twice. The entire tool exists to make a careful human approval fast and well-informed.

Who it's for

Fleet managers, finance and AP teams, and the drivers and front-line managers who live this every month. If you can describe how a trip becomes a reimbursement in your world — the rate, the rules, and what "that looks wrong" means — you can build this.

You've got this — open the plan, paste the first prompt, and you'll be logging your first real trips and receipts this afternoon.