Cash vs Accrual Accounting for Montana Small Businesses
The choice between cash and accrual accounting isn't just bookkeeping trivia — it determines when income hits your tax return, whether your P&L reflects reality, and in some cases whether the IRS will even let you pick. Here's the practical version for Montana small business owners.
How each method actually works
Cash basis: you recognize income when money hits your bank account and expenses when they leave it. If you invoice a customer in December and get paid in January, that income is taxed next year.
Accrual basis: you recognize income when you earn it (usually when you invoice) and expenses when you incur them, regardless of when cash moves. Your P&L reflects the economic reality of the period, not just the timing of deposits.
Which one you're allowed to use
Most small businesses in Montana under $30 million in three-year average gross receipts can use cash basis for tax purposes — this is the Tax Cuts and Jobs Act threshold that keeps expanding with inflation.
You may be forced onto accrual if you carry inventory as a material income-producing factor, though the small-business exception now lets most retailers and contractors stay on cash for tax even while tracking inventory internally.
C-corporations over the gross-receipts threshold and most partnerships with a C-corp partner must use accrual.
The tax implications
Cash basis defers tax on receivables — you don't pay tax on money you haven't collected. For a growing service business, that's a meaningful timing benefit.
Accrual matches revenue with the expenses that produced it. For a business with big year-end receivables and payables, accrual can actually reduce taxable income in a given year even though cash basis usually defers more.
When management reporting should differ from tax
It's completely normal — and often smart — to keep books on accrual for management decisions (so you see real margins by job or month) while filing taxes on cash basis. Good bookkeeping software supports both views.
Contractors, agencies, and any business with long project cycles benefit the most from accrual internally. Cash-only reports mislead you when a big invoice hits or a big bill is paid.
How to switch methods
Changing accounting methods for tax purposes requires filing Form 3115 with the IRS and calculating a Section 481(a) adjustment to avoid double-counting. It's not something to DIY the first time.
The upside: many method changes are automatic (no IRS approval needed), and the adjustment can often be spread over four years to soften the tax impact.
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.