[header] How to account for petty cash [title] Purchase a lock box. [step] When you are starting a petty cash fund, you need to buy a lock box that will hold the cash available for use and the receipts for what has been spent. You need a small, metal box that can easily fit within a desk drawer. 
This box can either have combination lock or have a key lock, depending on what is best for your particular office. Either way, it needs to be extremely secure to deter people from tampering with the box.