Cash vs. Accrual Accounting: How Does the Choice Affect a Small Business's Taxes?
Two businesses can do exactly the same amount of work in a year and still report very different taxable income, simply because of when they count money as earned or spent.
The short answer
Cash-basis accounting reports income when it’s actually received and expenses when they’re actually paid, while accrual-basis accounting reports income when it’s earned and billed and expenses when they’re incurred, regardless of when cash changes hands. The choice between the two changes the timing of when income and expenses show up on a tax return, which can shift taxable income from one year to another even though the underlying business activity is identical.
What changes under cash-basis accounting
Under cash-basis accounting, an invoice sent in December but paid in January counts as income in the year it was actually received — January, in this example — not the year the work was done. The same logic applies to expenses: a bill received in one year but paid in the next is counted as an expense when the payment goes out. This method tends to track fairly closely with the actual cash sitting in a business’s accounts, which is part of why many small, simpler businesses use it.
What changes under accrual-basis accounting
Under accrual accounting, that same December invoice counts as income in December, when the work was billed, even if payment doesn’t arrive until the following year. Expenses work the same way in reverse — a cost is recorded when it’s incurred, not when it’s actually paid. This method tends to give a more complete picture of a business’s activity during a given period, since it matches income and expenses to when they actually happened rather than when cash moved, but it can also mean paying tax on income that hasn’t been collected yet.
Why the timing difference matters
The practical effect shows up most clearly around year-end. A business that bills a lot of work in December but doesn’t get paid until January will report that income in different tax years depending on which method it uses. This timing shift is also why an unpaid invoice can potentially be deducted as a bad debt under accrual accounting but generally can’t under cash-basis accounting — the bad debt deduction only makes sense if the income was already counted as taxable income in an earlier period.
Who can generally choose which method
Not every business has unlimited flexibility to pick either method — eligibility can depend on factors like the size of the business, its structure, and whether it carries inventory as part of its operations. Larger businesses or those with more complex operations may be required to use accrual accounting, while smaller service-based businesses often have more flexibility to choose. Because these eligibility rules can be specific and change over time, it’s worth treating the general distinction as a starting point rather than assuming any given business automatically qualifies for either method.
The bottom line
Cash and accrual accounting aren’t just bookkeeping preferences — they genuinely change when income and expenses land on a tax return, which can shift how much is owed in a given year even when nothing about the underlying business activity is different. This choice ripples into other decisions too, from how freelance and self-employment income gets reported on a Schedule C to whether a bad debt deduction is even available. Because the right method depends on the specifics of a business and its eligibility, it’s a decision worth understanding in general terms before assuming either approach applies automatically.