How to Categorize Business Expenses Correctly
Every transaction you book goes to an account. Get the categorization wrong and your gross margin is meaningless, your tax return under- or over-states deductions, and your accountant charges you extra to re-categorize at year-end.
The categorization principle
Ask two questions: is this an expense at all (or is it an owner draw, loan payment, or asset purchase)? And if it is an expense, is it directly tied to producing revenue (COGS) or is it overhead?
Getting these two questions right eliminates 90% of categorization mistakes.
Common categorization mistakes
Booking loan principal payments as expense. Only interest is deductible; principal reduces the loan balance on the balance sheet.
Booking asset purchases (equipment, vehicles) as expense. Anything over your capitalization threshold ($2,500 for most businesses) goes to fixed assets.
Booking owner draws as 'Owner Salary' expense in an LLC or sole prop. Draws are equity distributions, not expense.
Booking sales tax collected as revenue. It's a liability until you remit it.
Lumping everything into 'Miscellaneous' or 'Office Supplies.' You lose the ability to see where money actually goes.
The categories that matter for taxes
Meals (50% deductible — usually). Vehicle (mileage or actual, but pick one and stick with it). Home office (if you qualify). Travel (100% for legitimate business travel). Advertising. Professional services. Insurance. Rent. Utilities. Repairs and maintenance. Depreciation.
The IRS Schedule C and Form 1120-S expense lines mirror these. Structuring your COA to match makes year-end trivial.
When in doubt, ask
If you don't know how to categorize a transaction, don't guess. Use QuickBooks' 'Ask My Accountant' account (or create one) and ask before month-end. A five-minute question saves an hour of cleanup later.
A quick disclaimer
This article is general information for Montana small business owners, not tax, legal, or accounting advice for your specific situation. Rules change, and how they apply depends on facts we don't know about you. Before acting on anything you read here, talk to a qualified professional. If you're a Montana business owner and want a real conversation about your books, payroll, or tax, that's what Marlow Accounting is here for — call 406-290-1214 or schedule a discovery call.