The 'Pay as You Go' and Basic Plans each contain a specified number of allocated features. Customers on these plans can set up additional features beyond the allocated numbers that are provided by the plans, if they need more of a particular feature(s). Each additional feature that you create will add a certain amount to the cost of your monthly bill (depending on how much the feature costs and how many of each are enabled). You can keep track of your account's monthly invoice in the OnSIP Admin Portal. The monthly total that will be due can be seen by clicking on the "Account" tab, then clicking on the "Configure plan" link in the Plans box. This invoice that appears includes all enabled features that will be billed on your upcoming month's invoice.