You drove 4,000 miles for work last year. You claimed zero. Why? You forgot to write them down.

The standard mileage deduction is real money. In many countries it's over 60 cents per mile. That's $2,400 you handed back to the tax office because you had no record. A shoebox of gas receipts won't save you. A guessed number gets flagged in an audit.

Here's how to build a private mileage log you actually keep up with.

Why not just use a mileage app?

Most free mileage trackers run on your phone's GPS all day. They know every place you drive — the pharmacy, the school, the address you visit on Fridays. That data gets sold. "Free" apps make money one way, and it isn't kindness.

A self-hosted log stays on your machine. No company sees where you went. And when the tax office asks for proof, you export a clean spreadsheet instead of begging an app that shut down last spring.

The 20-minute setup

You want a simple database with a form. Grocy is overkill, so use NocoDB — a self-hosted spreadsheet that looks like Airtable.

Run it with Docker on any old PC or a $5 mini server:

docker run -d --name mileage \
  -p 8080:8080 \
  -v /home/you/nocodb:/usr/app/data \
  nocodb/nocodb:latest

Open http://your-server-ip:8080, create a table called Trips, and add these columns:

  • Date
  • Start (address or place name)
  • End
  • Miles
  • Purpose (client meeting, supply run)
  • Business or Personal

That's it. Every trip becomes one row.

Make logging painless

A log you have to sit down for is a log you'll abandon. Two tricks:

  1. Bookmark the form on your phone home screen. NocoDB gives you a shareable form link. Tap it, type four fields, done — right in the parking lot.
  2. Log the odometer, not the route. Write the start and end mileage. The math is done for you. No GPS needed, no tracking, no battery drain.

The column that saves you in an audit

Add a Notes field and drop in the client name or the reason. Tax auditors love context. "Drove to meet J. Patel re: invoice #204" beats a bare number every time. It turns a suspicious figure into a believable record.

Back it up

Your deduction lives or dies on this file. Once a month, export the table to CSV and drop it in your regular backup. If the server dies, your money-saving evidence survives.

Your one action today

Spin up NocoDB, make the Trips table, and log the very next drive you take — even the one to the store. Building the habit on a small trip is how you catch the big ones. Next April, you'll claim every mile instead of guessing.