Business expenses are recorded by debiting the specific expense account and crediting whichever account gave up value, most often Cash or Accounts Payable. That two-sided entry is the whole mechanic of how expenses are recorded with debits and credits, and it holds whether you’re logging a utility bill, a payroll run, or a depreciation charge. What changes from one transaction to the next is the credit side, because it reflects how and when you actually pay.
The reason the debit sits on the expense account comes from the accounting equation. Assets equal liabilities plus equity, and expenses reduce equity. When your business consumes cash or takes on a bill to deliver its product, the owners’ stake shrinks by that amount, and the debit to the expense account is how the ledger captures that shrinkage.
The Core Rule for Expense Accounts
Expense accounts carry a normal debit balance. They go up with debits and down with credits. If you remember one thing, make it this: recording an expense always begins with a debit to the expense account. The credit side then depends on the payment.
- Paid in cash the same day: credit Cash.
- Received an invoice you haven’t paid: credit Accounts Payable.
- Using up something you paid for in advance: credit the prepaid asset account.
Credits to an expense account are uncommon and usually mean one of two things. Either you’re correcting an earlier error, or you’re running the year-end closing entries that zero out temporary accounts and roll their balances into retained earnings. Skipping closing entries lets last period’s costs bleed into the new period’s income statement, which is exactly the kind of error that snowballs.
Paying in Cash
When your business pays at the point of sale or writes a check the same day, the entry is short. Debit the specific expense account (Office Supplies, Travel Expenses, Utilities, and so on) and credit Cash for the same amount. Both sides settle immediately, and the expense lands on the income statement in the period you paid.
This is the foundation of cash-method accounting, which the tax code allows for entities with average annual gross receipts of $32 million or less over the prior three years.1Office of the Law Revision Counsel. 26 U.S. Code 448 – Limitation on Use of Cash Method of Accounting The base figure in the statute is $25 million and is adjusted for inflation each year. Below that line, bookkeeping stays simpler because you only record expenses when money actually leaves the account.
Petty Cash
Small out-of-pocket purchases work a little differently. You set up the fund by debiting Petty Cash and crediting Cash. As people spend from the box they keep receipts, but no entry is made yet. The entry happens at replenishment: debit each expense account for what the receipts show and credit Cash for the total put back in the box. Petty Cash itself isn’t touched, because the account is meant to sit at its original balance.
If the receipts don’t line up with the missing cash, the difference posts to a Cash Over and Short account. A shortage is debited, an overage is credited. Small gaps happen; a pattern of shortages is worth investigating.
Buying on Credit
When your business receives goods or services before paying, accrual accounting requires recognizing the expense at the time you receive the benefit, not when the check clears. The entry is a debit to the expense account and a credit to Accounts Payable. That credit creates a liability reflecting what you owe, usually payable within 30 to 60 days.
Matching costs to the period they helped produce revenue gives a more accurate picture of results. A $4,000 shipment of raw materials received in March but paid in April belongs to March’s expenses, because that’s when the materials were used. Recording it in April would understate March’s costs and overstate March’s profits.
When the invoice is eventually paid, the entry has two lines: debit Accounts Payable to clear the liability, and credit Cash. The expense account isn’t touched again, because the cost was already recognized when the invoice came in. This is where accrual-basis errors most often creep in. Recording the expense once when billed and again when paid inflates costs and throws the income statement off.
Adjusting Entries at Period End
At the close of each accounting period, adjusting entries pull the books into line with what actually happened. They catch costs incurred but not yet booked and shift prepaid amounts into expense as the benefit is used up. Financial statements produced without these adjustments almost always look better than reality.
Depreciation
Long-lived assets like equipment or vehicles are expensed across their useful lives, not all at once. Each period, debit Depreciation Expense and credit Accumulated Depreciation, a contra-asset account that lowers the asset’s book value on the balance sheet. A $50,000 machine with a ten-year useful life produces $5,000 of depreciation expense a year under the straight-line method.
Tax treatment can differ. Section 179 lets you deduct the full cost of qualifying equipment in the year it’s placed in service, up to $2,560,000 for tax years beginning in 2026.2Office of the Law Revision Counsel. 26 U.S. Code 179 – Election to Expense Certain Depreciable Business Assets The deduction begins phasing out once total qualifying property placed in service exceeds $4,090,000. That creates a gap between your financial-reporting books, which show gradual depreciation, and your tax return, which may show the full deduction in year one.
Prepaid Expenses
When you pay in advance, the outlay first goes on the balance sheet as an asset. An annual insurance premium, for example, is booked with a debit to Prepaid Insurance and a credit to Cash. Each month, an adjusting entry moves one month of coverage into expense: debit Insurance Expense, credit Prepaid Insurance. After twelve months the prepaid asset reaches zero and the full premium has passed through as expense across the periods it covered.
Accrued Expenses
Accrued expenses run the other way. These are costs you’ve incurred but haven’t paid or been billed for yet. Wages are the classic example. If the pay period closes on a Friday but the month ends on a Wednesday, three days of wages are earned but not yet paid. The adjusting entry debits Wages Expense and credits Wages Payable. When payday arrives in the next period, you debit Wages Payable and credit Cash.
Recording Payroll
Payroll is usually the largest expense category for any business with employees, and it generates more journal entries than almost any other cost because of the taxes stacked on top of gross wages.
The base entry debits Wages Expense (or Salaries Expense) for the gross amount earned. The credit side splits several ways. Cash is credited for the net pay actually delivered to employees, and separate liability accounts are credited for each tax withheld from their checks: federal income tax, Social Security, and Medicare. Those withheld amounts are not your expense. They’re money you’re holding in trust for the government.
Your expense is the employer’s matching share of payroll taxes. Employers pay 6.2% of wages for Social Security and 1.45% for Medicare, matching what’s withheld from the employee.3Office of the Law Revision Counsel. 26 U.S. Code 3111 – Rate of Tax That match gets its own entry: debit Payroll Tax Expense and credit the matching tax liability accounts. Your true labor cost runs roughly 7.65% above gross wages before any other benefits enter the picture.
Withheld and matched taxes have to be deposited with the IRS on a schedule tied to your total tax liability, and they’re reported quarterly on Form 941. The filing deadlines are April 30, July 31, October 31, and January 31.4Internal Revenue Service. Instructions for Form 941 Withheld employee taxes are treated as trust fund taxes, and the IRS can hold owners and officers personally liable through the Trust Fund Recovery Penalty, which adds a penalty equal to 100% of the unpaid tax.
Deciding Whether to Expense or Capitalize First
Before you write any journal entry, decide whether the cost belongs on the income statement now or on the balance sheet as an asset. Federal tax law allows a deduction for expenses that are both “ordinary” (common in your industry) and “necessary” (helpful and appropriate for the business).5Office of the Law Revision Counsel. 26 U.S. Code 162 – Trade or Business Expenses Rent, utilities, office supplies, and routine repairs are expensed immediately.
Costs that buy something with a useful life beyond one year, such as equipment, vehicles, or building improvements, are capitalized. The purchase sits on the balance sheet as an asset and is expensed gradually through depreciation or amortization. The IRS offers a de minimis safe harbor that lets you expense items costing up to $2,500 per invoice, or $5,000 if you have audited financial statements, even when they’d otherwise qualify as capital assets.6Internal Revenue Service. Tangible Property Final Regulations A $2,000 laptop can be written off in full under this rule rather than depreciated across several years.
Documentation for Every Entry
Every expense entry needs a source document. The IRS expects records that identify the payee, the amount, proof of payment, the date, and a description of what was purchased.7Internal Revenue Service. What Kind of Records Should I Keep Receipts, invoices, canceled checks, bank statements, and electronic funds transfer confirmations all qualify.
Businesses that run into trouble during audits usually aren’t the ones that booked fraudulent expenses. They’re the ones that booked legitimate expenses and can’t prove it later. A $500 client dinner is deductible if you kept the receipt and a note about who attended and what was discussed; without that, an auditor can disallow the same dinner as an unexplained write-off. Attaching documentation to each entry at the time you record it, rather than reconstructing months after the fact, is worth more than any bookkeeping shortcut.