KEY TERMS Imprest system - System commonly used to account for petty cash, whereby the total amount of cash in the petty cash float is periodically topped up to a given limit. At all times, the petty cash vouchers plus the notes and coins in the float should be equal to this limit. Petty cash float - The value of notes and coins held at any point in order to make petty cash payments. It should be held in a secure location and under the control of a responsible person. Petty cash voucher - Document kept in the petty cash giving details of money paid out and the reasons for the expense.