Why Cash and Accrual Results Differ
Cash collected during a period is not necessarily the same as revenue earned in that period. A customer may owe for work already completed, or may pay before work is done. Similarly, cash paid is not necessarily the same as expense incurred: a business may owe a supplier for an expense already incurred or pay in advance for a future benefit. Accrual accounting records revenue when earned and expense when incurred, so the related balance-sheet accounts explain the timing difference.
The key is to use the change in each related account, calculated as its ending balance minus its beginning balance. An increase in receivables means some earned revenue has not yet been collected; an increase in unearned revenue means some cash collected has not yet been earned. For expenses, an increase in payables means some incurred expense has not yet been paid, while an increase in prepaid expenses means some cash paid has not yet become an expense.
The Reconciliation Formulas
Let \(C\) be cash collected from customers, \(R\) be revenue earned, \(P\) be cash paid for the expenses under consideration, and \(E\) be expense incurred. Use \(\Delta AR\), \(\Delta U\), \(\Delta AP\), and \(\Delta Prepaid\) for the changes in accounts receivable, unearned revenue, accounts payable, and prepaid expenses, respectively.
These formulas apply when the listed balance changes arise from the revenue or expense activity being reconciled. Assume there are no write-offs, noncash revenue or expense items, acquisitions, reclassifications, or other adjustments affecting these accounts. If such items occur, the account rollforwards must include them; the simple formulas cannot be applied without modification. Also, cash paid for buying equipment or repaying debt is not an expense payment and should not be included in \(P\).
Why the Signs Work
The formulas follow from account rollforwards. For receivables, earned credit sales increase the balance and customer collections reduce it. Thus, under the stated assumptions, the change in receivables equals credit revenue earned minus cash collected against those receivables. An increase in receivables therefore represents revenue not yet collected.
Unearned revenue moves in the other direction: advance customer receipts increase it, and earning revenue previously deferred reduces it. Its change is advance receipts minus revenue recognized from those advances. Combining these rollforwards with revenue earned for cash in the period gives the cash-to-revenue relationship:
The expense relationship follows the same account-rollforward logic. Accounts payable increase when an expense is incurred on credit and decrease when cash is paid against the balance. Prepaid expenses increase when cash is paid before the benefit is consumed and decrease when that benefit becomes an expense. Therefore:
The practical sign test is straightforward: an increase in an asset representing an uncollected amount or unused prepayment has a different effect from an increase in a liability representing an unpaid expense or unearned receipt. Do not treat all increases alike; identify what the account balance represents before applying a sign.
Worked Example: Reconciling Revenue With Receivables and Customer Advances
A consulting firm collected $286,000 from customers during a quarter. Accounts receivable were $34,000 at the beginning and $51,000 at the end. Unearned revenue was $12,000 at the beginning and $8,000 at the end. Assume all changes relate to consulting services, with no write-offs or other adjustments. Find revenue earned and verify the reconciliation.
Method. Use the revenue formula, first calculating each ending-minus-beginning change. This avoids mistaking the decrease in unearned revenue for an increase in revenue deferred.
Accounts receivable changed by \(51{,}000-34{,}000=17{,}000\). Unearned revenue changed by \(8{,}000-12{,}000=-4{,}000\). Substitution gives:
Revenue earned was $307,000. Check by rearranging the formula: \(C=R-\Delta AR+\Delta U=307{,}000-17{,}000-4{,}000=286{,}000\), equal to the stated collections. The method avoids the common mistake of subtracting the $4,000 decrease in unearned revenue as though it were an increase; the formula subtracts the change, so subtracting a negative adds $4,000.
Worked Example: Reconciling Expense With Payables and Prepayments
A design studio paid $198,000 in cash for operating costs during a year. Accounts payable related to those costs were $22,000 at the start and $31,000 at year-end. Prepaid operating costs were $6,000 at the start and $10,000 at year-end. Assume the balances change only through the costs in question and no noncash expenses are included. Calculate expense incurred and check it against cash paid.
Method. Add the increase in payables because some expense remains unpaid; subtract the increase in prepayments because some cash paid still represents a future benefit.
The payable change is \(31{,}000-22{,}000=9{,}000\). The prepaid change is \(10{,}000-6{,}000=4{,}000\). Therefore:
Expense incurred was $203,000. Verification: \(P=E-\Delta AP+\Delta Prepaid=203{,}000-9{,}000+4{,}000=198{,}000\), matching the cash paid. A common error is to add the prepaid increase: doing so would count the $4,000 future benefit as an expense of this year rather than subtracting it.
Combining the Revenue and Expense Reconciliations
The same logic can be applied to revenue and expense together. Their difference is accrual-basis income for the activities included. Cash collected less cash paid is the corresponding net cash amount. These two totals differ because the related asset and liability balances changed during the period.
This comparison is limited to the revenues and expenses covered by the reconciliation. It is not a complete cash flow statement: investing or financing cash flows, noncash expenses, taxes, and other items may also affect reported cash or income. The formula explains the timing differences for the accounts named, not every difference between profit and total change in cash.
Worked Example: Comparing Accrual Income With Net Cash
A software support firm collected $420,000 from customers and paid $267,000 for operating costs during a period. Accounts receivable increased from $40,000 to $55,000, unearned revenue increased from $18,000 to $30,000, accounts payable decreased from $29,000 to $24,000, and prepaid expenses decreased from $11,000 to $7,000. Assume all four balances relate to the stated operating activity and have no other adjustments. Find revenue, expense, accrual income, and net cash, then reconcile the difference.
Method. Reconcile revenue and expense separately, then compare their difference with collections less payments. This prevents mixing the signs for assets and liabilities.
The changes are \(\Delta AR=55{,}000-40{,}000=15{,}000\), \(\Delta U=30{,}000-18{,}000=12{,}000\), \(\Delta AP=24{,}000-29{,}000=-5{,}000\), and \(\Delta Prepaid=7{,}000-11{,}000=-4{,}000\).
Revenue earned is \(420{,}000+15{,}000-12{,}000=423{,}000\). Expense incurred is \(267{,}000-5{,}000-(-4{,}000)=266{,}000\). Thus accrual income is \(423{,}000-266{,}000=157{,}000\). Net cash from these activities is \(420{,}000-267{,}000=153{,}000\).
The difference is \(157{,}000-153{,}000=4{,}000\). The reconciliation also gives \((15{,}000-12{,}000)-(-5{,}000-(-4{,}000))=3{,}000-(-1{,}000)=4{,}000\). The two methods agree. The $1,000 difference between expense and cash paid is negative because the payable decrease exceeds the prepaid decrease: \(E-P=-5{,}000-(-4{,}000)=-1{,}000\).
Common Sign Errors and When to Pause
The most reliable way to avoid a sign error is to write every change as ending balance minus beginning balance before substituting. Then ask what the change means in plain language. For example, a negative change in unearned revenue means some previously collected cash has now been earned; a negative change in prepaid expenses means some earlier payment has now become an expense.
- Wrong: Revenue \(=C-\Delta AR-\Delta U\). This subtracts an increase in receivables, even though an increase means revenue earned but not yet collected.
- Correction: Revenue \(=C+\Delta AR-\Delta U\). Add the receivable increase, and subtract the unearned-revenue change.
- Wrong: Expense \(=P-\Delta AP+\Delta Prepaid\). This treats an unpaid increase in payables as reducing expense and counts an increase in prepayments as current expense.
- Correction: Expense \(=P+\Delta AP-\Delta Prepaid\). Add the payable increase and subtract the prepaid increase.
A change in the account balance may have causes outside the activity being reconciled. For instance, a receivable written off without collection changes the account but does not represent cash collected or revenue earned in the period. If that occurs, identify and account for the separate cause rather than applying the simple formula blindly. The formulas are useful precisely because their assumptions are explicit.
Check Your Understanding
For each problem, calculate ending-minus-beginning changes before using the relevant reconciliation.
- A repair service collected $164,000. Accounts receivable rose from $21,000 to $29,000, while unearned revenue fell from $5,000 to $2,000. Assuming no other changes, find revenue earned. (Answer: $175,000)
- A laboratory paid $92,000 for specified operating expenses. Accounts payable fell from $14,000 to $9,000, and prepaid expenses rose from $3,000 to $8,000. Find expense incurred. (Answer: $82,000)
- A training provider collected $310,000. Receivables decreased from $46,000 to $38,000, and unearned revenue decreased from $16,000 to $10,000. Find revenue earned and verify that the result is consistent with collections. (Answer: Revenue earned is $308,000; \(308{,}000-(-8{,}000)+(-6{,}000)=310{,}000\))
- A maintenance business paid $151,000 for expenses. Accounts payable decreased from $27,000 to $19,000. Prepaid expenses began at $12,000. If expense incurred was $145,000, what was the ending prepaid-expense balance? Assume no other changes. (Answer: $10,000)
- A firm collected $500,000 and paid $340,000 for the operating activity in question. Receivables increased by $20,000 and unearned revenue increased by $7,000. Payables increased by $12,000 and prepaid expenses increased by $3,000. Find accrual income and net cash, and state their difference. (Answer: Accrual income is $164,000; net cash is $160,000; accrual income exceeds net cash by $4,000.)