Each business unit can add custom fields to purchase orders and invoices. These can be dropdown options, date pickers, or free text.
For invoice categories such as credit card purchases, we recommend adding an “invoice type” dropdown menu to your custom fields for invoices with options such as “Standard invoice”, “Credit card purchase”, “Proforma invoice”, etc. This data can then be used for reports, filtering, workflow, and (for certain accounting packages) included as part of the export.