Key takeaways
What this article covers, in order:
- The shoebox problem
- How the imprest system works
- Rules that make petty cash work
- When the fund size is wrong
- Should you even have petty cash?
- Common petty cash mistakes in the books
To track petty cash properly, keep a fixed amount in the box (say $300), log every payout with a receipt as it happens, and top the box back up to that fixed amount on a regular schedule. The top-up is when the expenses hit your books. That method has a name, the imprest system, and it turns petty cash from a mystery into something you can reconcile in five minutes.
The shoebox problem
Tony runs a four-bay auto repair shop in Sacramento. There's a cash drawer in the back office that everyone dips into: a $40 parts run when the supplier's driver is late, stamps, a pizza for the crew on a long Saturday. Receipts go in a shoebox. Sometimes.
Every few months Tony's bookkeeper asks what the $500 ATM withdrawal in the bank feed was for. Tony shrugs, she codes it to "Miscellaneous," and nobody's happy. Over a year, a few thousand dollars of real business expenses end up as an unexplained lump, and there's no way to tell whether the drawer is short because of a math slip or because someone's helping themselves.
The fix isn't complicated. It just needs a few rules everyone follows.
How the imprest system works
The idea is simple: the petty cash account in your books always holds the same balance. The physical box moves between "full" and "partly spent," but the books only change when you top it up.
- Set up the fund. Write a check or withdraw a fixed amount from the business bank account.
- Spend from it with a receipt. Every payout gets a slip and, ideally, the original receipt.
- Replenish. When the box runs low, or at month-end, add up the slips, record those expenses, and withdraw enough to bring the box back to the fixed amount.
- Check that it balances. Cash in the box plus receipts should always equal the fixed amount.
Step 1: set up the fund
Tony decides $300 covers about a month of small purchases. He withdraws $300 from business checking on Oct 1, 2026.
| Account | Debit | Credit |
|---|---|---|
| Petty Cash | $300.00 | |
| Business Checking | $300.00 |
That's a transfer between two asset accounts. No expense yet. If you see this withdrawal in your bank feed, categorize it to the Petty Cash account, not to an expense.
Step 2: log every payout
Keep a simple log in the box or a shared sheet. One row per payout.
| Date | Paid to | What for | Amount | Receipt? | Who |
|---|---|---|---|---|---|
| Oct 3, 2026 | Valley Auto Parts | Brake hose, rush | $142.15 | Yes | Ray |
| Oct 9, 2026 | Post office | Certified mail | $38.25 | Yes | Tony |
| Oct 14, 2026 | Hardware store | Shop towels, degreaser | $61.00 | Yes | Ray |
| Oct 24, 2026 | Pizza place | Saturday crew lunch | $27.00 | Yes | Tony |
| Total | $268.40 |
If someone loses a receipt, they fill in a slip saying what they bought, when and why, and sign it. That's not as good as a receipt, but it's a lot better than nothing.
Step 3: count and replenish
On Oct 31, 2026, Tony counts the box. Based on the log, there should be $300.00 less $268.40, which is $31.60. He counts $29.10.
The box is $2.50 short. Could be a coin miscounted on change, could be a missing slip. At this size it's a rounding issue, not a crisis. He records it honestly rather than fudging a receipt.
To bring the box back to $300, he withdraws $270.90 ($300.00 minus the $29.10 on hand). The entry:
| Account | Debit | Credit |
|---|---|---|
| Parts and Materials | $142.15 | |
| Postage | $38.25 | |
| Shop Supplies | $61.00 | |
| Meals | $27.00 | |
| Cash Over and Short | $2.50 | |
| Business Checking | $270.90 |
Debits total $270.90, credits total $270.90. Notice the Petty Cash account itself isn't touched. It still says $300 in the books, and the box now physically holds $300 again.
Step 4: what if the box is over?
Occasionally there's more cash than expected, usually from incorrect change given back. The Cash Over and Short account takes a credit in that case. Over time, small overs and shorts should roughly wash out. A pattern of shortages is a signal to look closer.
Rules that make petty cash work
Petty cash fails socially more often than technically. These rules are what make it reliable:
- One custodian. One person holds the key and does the counts. Others request cash from them.
- A per-purchase cap. For Tony, anything over $150 goes on the business card instead. Petty cash is for small, immediate needs.
- No IOUs without a slip. If someone borrows $20 for the day, there's a signed slip in the box until it's returned.
- No personal loans from the box. Ever. It makes reconciliation impossible.
- Count on a schedule, and occasionally by surprise. A monthly count plus an unannounced one now and then keeps everyone honest without making it feel like an accusation.
- Keep receipts with the replenishment. Staple or scan them and attach them to the replenishment record. That's your audit trail.
When the fund size is wrong
If you're replenishing every week, the fund is too small. If cash sits untouched for three months, it's too big, and that's cash that could be earning interest or paying a bill.
To change the fund size, record the difference as a transfer. Raising Tony's fund from $300 to $400 means debiting Petty Cash $100 and crediting Checking $100. That's the only time the Petty Cash account balance itself should move.
Should you even have petty cash?
Honest question. Many small businesses can get rid of it entirely.
Reasons to keep it:
- Vendors who only take cash (some parts runners, farmers markets, tips).
- Very small, frequent needs where using a card is impractical.
Reasons to drop it:
- Business debit or credit cards handed to the people who need them create an automatic record in your bank feed.
- No count, no shortages, no shoebox.
- Card spending can be categorized like any other transaction.
If you keep a small fund, keep it small. A lot of businesses settle on $100 to $300.
Common petty cash mistakes in the books
- Expensing the initial withdrawal. The $300 that set up the fund isn't an expense. It's cash moving from the bank to a box.
- Expensing ATM withdrawals for petty cash as "Miscellaneous." Same issue. The expense is recorded at replenishment, by category.
- Never reconciling the box. If the Petty Cash account says $300 but nobody's counted the drawer in a year, the number in your books is a hope, not a fact.
- Mixing petty cash with cash sales. Customer cash payments belong in a separate drawer and get deposited. Mixing them makes both impossible to track.
How HelloBooks helps
HelloBooks doesn't count the drawer for you, but it makes the bookkeeping side easy. When you connect most US banks and credit cards (or import a bank statement CSV), the fund setup and replenishment withdrawals land in a review list where you confirm or change the category: the setup withdrawal to Petty Cash, and each replenishment to the expense categories from your log. On every plan, including Free ($0, no credit card, no expiry, up to 200 transactions a year), you get the P&L and Balance Sheet where those expenses and the fixed fund balance show up. Your bookkeeper can be invited into the same books to review it. See automated bookkeeping and accounting for retail businesses.
FAQs
What is petty cash in accounting?
A small amount of cash kept on hand for minor business expenses. It's recorded as an asset account in your books.
How much should a small business keep in petty cash?
Enough to cover roughly a month of small purchases. For many small businesses that's $100 to $300.
When do petty cash expenses get recorded?
Under the imprest system, at replenishment. You record each expense category from the receipts and write a check or withdrawal to refill the fund.
What if petty cash doesn't balance?
Record the small difference to a Cash Over and Short account. If shortages repeat or grow, review who has access and tighten the rules.
Is the money used to set up petty cash an expense?
No. It's a transfer from your bank account to the Petty Cash asset account.
Keep the box small, keep the log honest, and petty cash stops being the mystery line in your books.
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