Zip Biz is a reusable account. For any purchases you make during the month you will receive a statement with your closing balance on the 1st day of the following month. You have until the last day of your statement month to pay off that balance with no fees.
Here’s an example:
If you make your first purchase on the 1st of March for $39, you will receive a statement on the 1st of April with the closing balance of $39 (assuming you don't make any more purchases) which you will need to pay off by the 30th of April for no fees.
Should you need more time you can elect to Part Pay. This will enable you to pay at least 1/4 of your statement balance and roll over your balance to the next month. If Part Pay is enabled a 2.5% fee will be added to your account.