How to Categorize Small Business Bank Transactions (Free Chart of Accounts Guide)

If you're staring at a year of bank/card transactions trying to figure out which are "Office Supplies" vs "Software & Subscriptions" vs "Meals & Entertainment," the actual bottleneck usually isn't effort — it's not having a consistent category list to check against, so every transaction becomes its own small judgment call.

1. Start with a fixed category list, not ad hoc judgment

The single biggest speed-up in categorising transactions is deciding your categories before you start, not while you're mid-spreadsheet. A stable list lets you pattern-match on vendor name instead of re-deciding "what is this?" every single row. Common small-business categories include:

• Software & Subscriptions — AWS, Google Cloud, Microsoft 365, Zoom, Slack
• Advertising & Marketing — Google Ads, Meta Ads, Mailchimp
• Contract Labor / Freelancers — Upwork, Fiverr, individual contractor names
• Rent, Utilities/Telecom, Payroll Expense, Payroll Processing Fees (kept separate from gross wages — a common mixing-up point)

A full 31-category reference, with real example vendor keywords and chart-of-accounts mapping, is free to reference at the bottom of this guide.

2. Watch for the judgment-call cases, not just the obvious ones

Most transactions match a category instantly by vendor name. The ones that actually cost time are the exceptions:

• Refunds — a refund is contra-revenue, not a fresh (negative) expense; booking it as a new expense line double-counts the reversal.
• Equipment above a materiality threshold — needs capitalising (an asset), not expensing outright, even though the transaction looks like a normal purchase.
• Ambiguous vendor names — a payment processor or holding-company name on the statement line that doesn't match what was actually purchased.

The safest practice here is the same one worth applying to any bulk data-cleanup task: flag the ones you're not sure about instead of guessing, and resolve the flagged list in one pass at the end rather than re-checking everything as you go.

3. Keep vendor-keyword matching consistent

Once you have a category list, most of the actual speed comes from keeping a running list of which vendor name maps to which category (e.g. "ADP" always → Payroll Processing Fees, not Payroll Expense). Write it down once, reuse it every month — this is exactly what turns categorisation from "read every row" into "check most rows against a list, only think hard about the new names."

4. When it's worth a ready-made reference

If you'd rather start from an already-built category list than assemble one from scratch, Engineer Tsai Studio's Chart of Accounts Starter Pack is exactly the list above, expanded to 31 categories with real vendor keywords and judgment-call notes, delivered as spreadsheet-ready CSV and API-ready JSON. One-time $7.

See the full category list and get the pack →

Scope

This guide and the Starter Pack are a categorisation reference, not tax or accounting advice — several categories genuinely need a licensed accountant's judgment, and the pack says so rather than guessing. US-oriented chart-of-accounts conventions; deductibility rules vary by jurisdiction.

Other Engineer Tsai Studio services: PDF tables to Excel, product image background removal. Questions: hello@tsaielectro.com.