Petty cash is kept in offices and departments for unforeseen needs. Imprest is used in programmes that manage small amounts of money. You put some extra money in the small-change box. Each outpost sells goods and services. If the account balance is too low, add more funds. The ability of a company to control and use even small sums of money increases security and dependability. Every financial transaction, no matter how small, is recorded and tracked. Small financial investments quickly add up.  https://blog.happay.com/petty-cash-management/