Petty Cash Controls That Actually Work (The Imprest System)
Petty cash is small money and a large risk — the place where controls are weakest, receipts vaguest, and quiet leakage most common. Here is the simple system that keeps small cash honest without smothering it in bureaucracy.
Every organization keeps some cash on hand for the small, immediate things a formal payment process would strangle — a matatu fare, a bag of nails, airtime, a delivery tip. Petty cash exists precisely to move faster than approvals allow, and that speed is exactly why it is the softest target for leakage in the whole of finance. The amounts are individually trivial, so nobody watches closely; receipts are casual or missing; and "I paid for it, trust me" is the default record. Multiply that across a year and petty cash becomes a meaningful, entirely preventable loss. The good news is that controlling it well takes one simple system, not vigilance.
The imprest system: the one idea that works
The proven method for petty cash is the imprest system, and its logic is elegant. You fix a float — say KES 10,000 — held by one custodian. Every disbursement is recorded with a voucher and, wherever possible, a receipt. At any moment, the cash remaining plus the vouchers spent must equal the fixed float. When the cash runs low, you reimburse exactly the total of the vouchers, restoring the float to its original amount. That single rule — cash on hand plus vouchers always equals the float — means the box can be reconciled in minutes and any shortfall is visible immediately, not at year-end.
The controls that make it hold
A petty cash system that stays honest
- A fixed float and a single named custodian responsible for it.
- A voucher for every disbursement — with date, amount, purpose, and recipient — plus a receipt where one exists.
- A per-transaction limit: anything above it goes through normal procurement, not petty cash.
- Cash plus vouchers reconciled to the float on a regular rhythm, and always before reimbursement.
- Reimbursement made only against the actual vouchers, so every top-up is backed by recorded spending.
- Vouchers coded to expense accounts, so petty cash spending appears in the books like any other cost.
The limit is the whole point
The most important and most ignored control is the per-transaction limit. Petty cash is for genuinely small, urgent items; the moment it becomes a way to buy meaningful things without approval, it has quietly become a hole in your procurement controls. A supplier payment split into several petty-cash disbursements to dodge an approval threshold is a classic red flag. Set a firm ceiling, and anything above it must go through a requisition — that one boundary keeps petty cash as the convenience it is meant to be rather than a bypass around every other control you have built.
Petty cash is a segregation-of-duties test in miniature
The same person should not hold the cash, approve the spending, and record it unchecked — that concentration is what makes leakage effortless. Even in a small organization, someone other than the custodian should periodically count the box against the vouchers. It takes minutes, and it is the single act that turns petty cash from a soft target into a controlled one. It is segregation of duties at its smallest and most practical scale.
Petty cash controls are humble, but they are a genuine test of whether an organization takes its money seriously, because they are where discipline is easiest to abandon. A business that runs a clean imprest system — floats fixed, vouchers complete, limits enforced, independently counted — almost always runs its larger finances well too. When petty-cash vouchers are captured in the same system as every other expense, coded and reconciled automatically, the smallest money gets the same honest treatment as the largest, which is exactly as it should be.
Keep even the smallest cash honest
See petty cash run on an imprest float, vouchers captured and coded, limits enforced, and the box reconciled in minutes.
Explore financial governanceFrequently asked questions
What is the imprest system for petty cash?
It is a method where petty cash is held as a fixed float assigned to one custodian, every disbursement is recorded with a voucher, and at any moment the cash on hand plus the vouchers must equal the float. When cash runs low, you reimburse exactly the total of the vouchers to restore the original float — so the box reconciles in minutes and any shortfall is immediately visible.
What controls does petty cash need?
A fixed float and a single named custodian, a voucher (and receipt where possible) for every disbursement, a firm per-transaction limit, regular reconciliation of cash plus vouchers to the float, reimbursement only against actual vouchers, and vouchers coded to expense accounts. Crucially, someone other than the custodian should periodically count the box independently.
Why is a per-transaction limit on petty cash so important?
Because without it, petty cash becomes a way to buy meaningful items without approval — a hole in your procurement controls. A classic red flag is a larger payment split into several petty-cash disbursements to dodge an approval threshold. A firm ceiling forces anything above it through a requisition, keeping petty cash a convenience rather than a bypass.
How does petty cash relate to segregation of duties?
Petty cash is segregation of duties at its smallest scale: the same person should not hold the cash, approve spending, and record it unchecked, because that concentration makes leakage effortless. Having someone other than the custodian periodically count the box against the vouchers — a task of minutes — is what turns petty cash from a soft target into a controlled one.
