It is possible to configure, enable and disable multiple modules that together constitute Orders in osCommerce v4. There exists a special Order Structure menu under Modules, which to a degree extends what used to be Order Totals in previous versions of osCommerce.
As with all the modules, we have made it possible for osCommerce developers to create an add their own Order structure modules.
Currently existing modules are as follows:
Their position (which can be re-arranged by using the drag-and-drop feature) defines how the system uses them for every order.
Each order total module has a number of settings, including restrictions and positioning:
It is possible to set, for example, the shipping fee, to include tax on the checkout pages, but exclude tax on the invoices.