| AccountingExportLibrary | Class AccountingExportLibrary |
| CollectivePaymentLibrary | Class CollectivePaymentLibrary |
| InvoiceLibrary | |
| OrderAmountsLibrary | Class OrderAmountsLibrary |
| PaymentLibrary | Class RefundLibrary |
| PayserviceProviderReportLibrary | Class PayserviceProviderReportLibrary |
| RefundLibrary | Class RefundLibrary |
| TaxRateLibrary | contains all functions that handle tax rates |
| VatIdCheckLibrary | checks at the german authority for taxes if a given vat id is valid |