A petty cash float is a fixed reserve of physical currency a business keeps on hand for small, immediate expenses like postage, delivery tips, or last-minute office supplies. It is run on the imprest system, which means the total value inside the box never changes: cash that leaves is replaced by a voucher of equal value, and the fund is periodically topped back up to the same starting amount. The mechanics are simple. The controls around it are where businesses either protect themselves or create exposure to fraud, tax problems, and messy books.
How the Imprest System Keeps the Float Balanced
The rule is one sentence: remaining currency plus the face value of all vouchers in the box always equals the original float. If someone takes $14 for a delivery tip, they leave a $14 voucher behind. The box still holds the same total value, just in a different mix of paper and coins.
That is what makes the float useful as a control. A supervisor can walk up at any moment, count the bills, add up the vouchers, and know immediately whether everything reconciles. Any shortage or overage is small enough to investigate on the spot, and the fund never quietly grows or drains without a paper trail.
Setting the Float Amount
Getting the starting amount right saves you from two equally annoying problems: replenishing every other day, or leaving a pile of cash sitting around as a theft target. Look at what your office actually spent on minor expenses over the past month or two, then set the float at roughly two to four weeks of that average. If your team spends about $60 a week on incidentals, a $200 float gives you enough runway.
Small teams under ten people commonly work with floats between $100 and $200. Mid-sized offices often land in the $200 to $500 range. These are starting points, not rules. What matters is that the amount tracks your actual spending pattern.
Per-Transaction Caps
Set a ceiling on how much can leave the box in a single transaction. Common limits run from $75 to $250. Anything above the cap should go through accounts payable as a check or electronic payment. A $400 vendor bill has no business coming out of the cash drawer. The cap keeps the fund from being drained by one or two large disbursements and preserves it for the small purchases it was designed to cover.
What Every Petty Cash Voucher Must Capture
Each time cash leaves the box, a voucher fills the gap. Skipping vouchers, or accepting incomplete ones, is where control breaks down. A complete voucher records:
- The exact date and dollar amount, matching the attached vendor receipt.
- The full name of the person receiving the cash.
- A specific business purpose. “Supplies” is not enough; “printer paper for marketing department” is.
- The original receipt, attached. No receipt, no reimbursement.
- Signatures from both the employee receiving the cash and the fund custodian.
- A general ledger account code assigned by the custodian, so the expense lands in the right category at replenishment.
Two signatures are more than a formality. They mean two people can independently confirm the transaction happened as described, which makes fabricating an expense considerably harder. Vouchers missing a specific purpose tend to get rejected at reconciliation, and the IRS backs that discipline up: you must keep records showing the amount, date, and essential character of any business expense you deduct.1Internal Revenue Service. Publication 463 – Travel, Gift, and Car Expenses
Replenishing the Fund
When the cash on hand hits a predetermined reorder level, the custodian gathers the completed vouchers, totals them, and presents the stack to a treasurer or senior manager. The reviewer confirms each voucher is legitimate, the math adds up, and every expense has a receipt attached. A check is then issued for the exact total of the vouchers, cashed, and the proceeds go back into the lockbox. The float is now restored to its original amount.
The Accounting Entry People Get Wrong
The Petty Cash account on your general ledger is touched only once, when the fund is first created. That entry debits Petty Cash and credits your main Cash account. At replenishment, you do not debit Petty Cash again. You debit the individual expense accounts the vouchers represent (office supplies, postage, meals) and credit Cash. The Petty Cash ledger balance stays flat from the day you open the fund until you formally increase, decrease, or close it.
How Often to Reconcile
Reconcile at least monthly, even if the fund has not hit its reorder level. Waiting for the cash to run low means weeks of transactions could pile up before anyone catches a shortage or a missing receipt. Monthly reconciliation also keeps replenishment entries in the accounting period they belong to.
When the Count Does Not Balance
Discrepancies happen. A cashier gives wrong change, a receipt slips behind the drawer, someone forgets to write a voucher. When cash plus vouchers does not equal the float, the difference posts to a Cash Over and Short account on the income statement. A shortage is a debit (expense); an overage is a credit (revenue).
Small, occasional differences of a dollar or two are normal friction. Persistent shortages in the same direction are a warning sign. The account exists to make that pattern visible instead of burying it in rounding.
Controls That Actually Prevent Theft
Petty cash is one of the easiest assets to steal, because it is by definition sitting in a box. The controls around it matter more than the controls around most accounts its size.
Separation of Duties
The person who holds the cash and disburses it should not be the same person who reconciles the fund. When one individual owns both roles, no independent check exists on their work. A custodian should handle daily transactions while a separate fiscal officer or manager performs the reconciliation and approves replenishment. In very small offices where that split is not practical, the owner or an outside accountant should periodically do the reconciliation.
Surprise Counts
Scheduled audits are useful for process review. Unannounced counts are what deter theft. When the custodian knows a manager could walk in at any time, count the box, and compare the total to the ledger, the temptation to borrow from the fund drops. Quarterly surprise counts are a reasonable baseline.
Physical Security
The fund belongs in a locked box inside a locked drawer or safe, not in an envelope in a desk. Access should be limited to the custodian and one backup. Personal cash should never sit alongside the fund; commingling creates confusion during counts and can mask shortages.
Tax Rules That Catch Petty Cash Users Off Guard
The fund feels informal, but the IRS treats cash spending the same as any other business deduction. A few areas trip businesses up.
Substantiation
To deduct a business expense, you need records showing the amount, date, and essential character of the purchase. For travel-related expenses of $25 or more, documentary evidence like a receipt or paid bill is specifically required.2eCFR. 26 CFR 1.274-5A – Substantiation Requirements Vouchers without a specific business purpose, or without a receipt attached, can be disallowed on audit.
Contractor Payments and the 1099-NEC Threshold
If you use petty cash to pay an independent contractor, those amounts add up across the year. For tax years beginning after 2025, the reporting threshold for nonemployee compensation on Form 1099-NEC rises to $2,000 annually, up from the previous $600 floor, with inflation adjustments starting in 2027.3Internal Revenue Service. 2026 Publication 1099 Track cumulative payments to any single contractor across all payment methods. Five $150 cash payments to a handyman is $750, and cash paid from the box counts toward the same total as checks and ACH.
Cash to Employees Is Wages, Not a Fringe Benefit
Employers can exclude certain small non-cash perks (an occasional company lunch, a holiday turkey) from employee income as de minimis fringe benefits. Cash and cash equivalents like gift cards never qualify, regardless of amount.4Internal Revenue Service. Publication 15-B, Employers Tax Guide to Fringe Benefits Handing an employee $20 from the box as a thank-you is technically taxable wages, and creates payroll tax obligations most custodians are not equipped to handle.
Record Retention
Keep records supporting a deduction for at least three years after filing the return that claims it. The period extends to six years if you fail to report more than 25% of gross income, and to seven years for losses from worthless securities or bad debt. Employment tax records require a minimum of four years.5Internal Revenue Service. How Long Should I Keep Records Many businesses adopt a blanket seven-year policy to cover the longest non-fraud scenario.
When to Retire the Lockbox
Physical cash is no longer the only way to handle small expenses, and for many offices it is no longer the best way. Low-limit corporate cards and virtual card platforms fill the same role with less friction. A virtual card can be generated instantly, assigned to a specific employee or single purchase, given a hard spending cap, and set to expire after one use. There is no lockbox to secure, no coins to count, and every transaction produces an automatic digital record with date, amount, and merchant already captured. If a card number is compromised, it can be frozen in seconds.
If you keep a physical float, the IRS allows scanning paper vouchers and receipts into an electronic system and destroying the originals, provided the digital copies are legible on screen and in print.6Internal Revenue Service. Automated Records The storage system must meet the requirements of Revenue Procedure 97-22, including testing to confirm reproductions are accurate before you shred anything.7Internal Revenue Service. Rev. Proc. 97-22 Photographing receipts and filing them in organized folders is a practical starting point, but verify your system actually meets the legibility standard before destroying the paper.