Guide · 2026-10-16

A simple system for tracking business expenses and mileage

A simple, repeatable system for logging business expenses, receipts and mileage in Google Sheets, so your records are ready when you need them.

Most small business owners don't hate bookkeeping because it is hard. They hate it because it piles up. A receipt in a coat pocket, a drive you don't quite remember, a subscription that renews quietly. By the time you sit down to sort it all out, the details are gone.

The fix is not a fancy system. It is a small, boring habit that takes a couple of minutes at a time, plus a spreadsheet that does the adding up for you. This guide lays out a simple way to track business expenses and mileage in Google Sheets.

This is a record-keeping guide, not tax advice. Rules about what you can deduct, how much, and what proof you need depend on where you live and on your situation. Check current rules with an accountant or your tax authority.

What you are really trying to capture

For every business expense, a good record answers five questions: when, who or where, what for, how much, and how you paid. For mileage, it is: when, from where to where, why, and how many miles. If you capture those at the time, you rarely have to reconstruct anything later.

You are also keeping proof. A link to a receipt or invoice next to each expense means you never hunt through email or a shoebox again.

Part 1: The expense log

Build, or start from, a table with these columns:

Date
Vendor (who you paid)
Category (software, supplies, travel, advertising, and so on)
Description (a few words on what it was for)
Amount
Payment method (card, cash, bank transfer)
Business-use % (for shared costs like a phone plan, where only part is for the business)
Receipt link

Keep the category list short, around ten to fifteen. Too many categories makes logging slow, and too few makes the summary less useful. Ask your accountant which categories they like to see, and use those names.

Shared costs

Some costs mix business and personal use. A business-use percentage column lets you enter the full amount and then count only the business share. How to decide the right percentage is a question for your accountant, but the spreadsheet should make it easy to record whichever figure you settle on.

Receipts

Make one folder in Google Drive for receipts, and give each file a name that starts with the date. When you log an expense, paste the file's link into the receipt column. A phone photo uploaded to Drive on the spot takes seconds. If your vendor emails receipts, forward them to a folder or save the PDFs when they arrive. The goal is that every row with money in it has a link that opens the proof.

Part 2: The mileage log

Mileage is easy to forget and hard to rebuild, so it's the one to log the same day. Your table needs:

Date
From and To
Purpose (for example client meeting, supplies run, site visit)
Vehicle (if you use more than one)
Miles, with a way to mark round trips so the distance counts both ways

Add a setting for your mileage rate per mile, because rates can change from year to year and differ by country. Look up the current figure from your tax authority or ask your accountant, and update it in one place so every total recalculates. Don't hard-code a rate inside the formulas.

For accuracy, many people use a maps app to check the distance, or note the odometer at the start and end of a trip. Pick one method and use it consistently.

Part 3: A weekly rhythm that sticks

You don't need to do it all daily. A rhythm that works for many people:

In the moment (30 seconds): snap the receipt or note the trip purpose on your phone.
Twice a week (5 minutes): type new expenses and drives into the sheet and paste the receipt links.
Monthly (10 minutes): open the summary. Does anything look odd? Are there rows with no receipt link? Fix them while you still remember.
At year end: print or export the summary for your accountant.

The monthly check is the one that pays off. A "missing receipts" counter on the sheet turns a vague worry into a number you can bring to zero.

Part 4: The summary that does the adding up

A tracker earns its keep when it totals things without effort. Useful views are:

Expenses by category, month by month, with a yearly total.
Total of the business-use portion, so shared costs count correctly.
Miles and the mileage amount by month, by purpose and by vehicle.
A count of expenses with no receipt link.

In Google Sheets this is done with functions like SUMIFS and QUERY, and it's worth building once and then leaving alone. If you start a new tax year, copy the file, clear the logs and keep your settings.

Pitfalls to avoid

Mixing personal and business spending in the same log. Keep the log business-only, and try to pay business costs from a separate card or account if you can. It makes everything cleaner.
Entering totals instead of individual expenses. A single line for "supplies, October" hides detail you may need later.
Letting the mileage rate get stale. Check it at the start of each year.
Skipping the purpose. A trip with no purpose is hard to defend and hard to remember.
Relying on memory. Memory is the first thing to fail.

Google Sheets limits

A plain log of a few thousand rows is fine in Sheets. Very large logs with many formulas can be slow, and phone entry is slower than on a computer. Sheets does not read your bank feed or your receipts, so you'll enter the data yourself, and it can't automatically flag duplicate entries unless you build a check. It also stores your data in your own Google account, which is convenient but means you should keep your account secure and back up important files.

Ready-made options

If you want the structure without building it, the Business Expense Tracker gives you an expense log with categories, business-use percentage, receipt links and a summary by category and month. The Business Mileage Tracker logs drives in seconds and summarizes miles and the mileage amount by month, purpose and vehicle for the tax year. Photographers who want income, expenses and mileage in a single file can look at the Photographer Bookkeeping & Mileage Tracker, which also shows monthly profit. For more, see all the Small Business Basics templates.