You can create custom fields for both Orders & Invoices – above the line items. We have plans to roll this functionality out though to other areas like line-items and suppliers.
You can create multiple custom fields and use their values to trigger workflows. A typical example will be a buying type – perhaps PO or Credit Card or say a buying category such as Capex or Opex.
To create a custom field, go to Business > Settings > Custom Fields
Provide a name, a description and then list option values separated by a semi colon.
Workflows
You can then use this value as a condition on a workflow entry point or step. An example is shown below: