To use the Invoice Approval Module, you first need to enable the module with the applicable setting in Invoice Options.
You might also want to review the other settings in Invoice Options and the other menus under Setup System, as some of the settings need to be configured if you're going to be using some of the more advanced features of this module, such as Invoice Discrepancies and Non-PO Invoices.
Please also review Types of Invoices and Workflow, which describes the different types of invoices and how they're used.
Prerequisites
The only mandatory prerequisite is the Purchasing Module (you obviously need to have a PO to match an invoice to).
While it's technically not mandatory, it would be unusual to use the Invoice Approval Module without the Receiving Module, since most people want to do a three-way match (i.e. match Purchase Order > Receipt > Invoice). However, if you don't want to enter receipts for your POs, you can do a two-way match (PO > Invoice), in which case you don't have to use Receiving.
Need a Little Help?
SpendMap offers a full range of Professional Services, such as training and implementation consulting. Just contact our Client Services Group, who can configure this module to your needs and help you get started faster.
