Custom fields for Expenses/Bills in ZohoBooks ?

Custom fields for Expenses/Bills in ZohoBooks ?

Hi there,
I wonder if there is a possibility to include custom fields when recording expenses/Bills in Zoho Books?.
In particular it is needed to include Vendor's Fiscal Identification Number, so that when we report expenses and Bills to our tax authority we can keep track of this critical ID number.

Anyone has a workaround for this?

Thank you all in advance