To be able to have us send your invoice by USPS mail, you will need to purchase stamps.

To buy stamps click on the "Store" tab.

Once in the store, you will see different options for buying stamps. To choose one, click on the price button, which will give you options to pay for the stamps.

The stamps are automatically added to your account once you have paid.

To view your stamps, you will go to the "Finance Tab">Invoices, and you can see the number of stamps you have on the top of that page. You can also buy more using the "Buy More" button.