To pay your bills, we'll first retrieve the funds from one of the bank accounts you've connected in Corpay One via Bill Pay > Payment Sources, and then proceed to pay your vendor. One each bill, you can manually specify which of these connected accounts you'd like Corpay One to use to complete the payment. 

With a receipt, specifying the payment account simply identifies which source was already used to pay the expense. These two simply processes are outlined here:

Find the bill for which you want to change the payment source on your dashboard and click on the small pencil icon in the Payment source field. Then select the desired payment source from the drop-down menu. Make sure you've added every bank account and payment source you'd like to appear as an option.

When integrate with your accounting system, you'll be able to import your list of payment sources (payment accounts) so they are available to you within Corpay One. Alternatively, you can manually create a custom payment source list in Settings > Lists. As long as the list is set to visible for receipts, you'll see it as a drop-down menu.

Find the receipt for which you want to change the payment account on your dashboard, and click on the payment account field. The list of payment accounts will appear in the drop-down, and you can select the appropriate account for the receipt at hand.