You can think of round-ups as spare change you'd get at the store, which would end up lost between sofa cushions or car seats anyway.
When you connect a Monitoring Account, which could be a credit or debit card, we fetch a daily list of transactions from that account. We then "round up" each purchase to the nearest full dollar.
Thus, a $2.49 coffee would get "rounded up" to $3, and we'd add the difference of 51¢ to your total round-ups, which you can see on your dashboard. A full-dollar transaction, like $15.00, would add a $1 round-up to the total.
When the total round-ups reach $10, we trigger a bond purchase of $10, just as if you would have purchased one bond manually. The funds get transferred via ACH to our bank, and we issue your bond when the final transfer clears.
Please note that when your accumulated round ups reach $10 and the bond is triggered for your account, the $10 cost is deducted from the bank account you originally linked as a funding source for your bond purchases (it does not come from the credit card you linked for monitoring the round ups).