The Billing page enables you to monitor your unit usage during the current subscription and have access to past invoices. This app is restricted to Portal users with the owner role and can be accessed by clicking the respective button in the app panel to the left.
Units and usage reporting differ in the sense that usage merely displays the raw number of translations performed in a certain amount of time, while billing takes into consideration commercial rules such unit ratio and fair usage. Units are the result of usage with billing rules applied. On the other hand, a subscription includes a certain amount of units.
In the image above you can quickly gather the information on how many units contained in your subscription have been used by each subscribed content type, distributed over the current billing period.
Free Units are the ones included in your subscription fee, while Payable units are the ones that have been used while exceeding the agreed number or that have been applied when incurring in a Fair Usage penalty.
Ask your CSM should you want to learn more about how units are consumed.
You can check on your past invoices on the Billing page. Here, your invoices will be listed with their number, due date, amount and payment status.
You can also download a PDF version of the invoice directly from the Portal by hovering over the entry and clicking the download button that appears at the end of the row.