Hi RCV,

             thank you for sharing knowledge. But I want to delete these custom fields permanently from QBO not only from Sales or invoice.

   let me fill you in why do I need that. I am trying to push PO information from one other software and I am using  QB API for that. there are some custom fields which I would like to fill and send it through API. but currently I am getting all those inactive fields which I am not using when I try to access custom fields using API. 

    https://blogs.intuit.com/blog/2019/04/08/enhanced-custom-fields-quickbooks-online-advanced/

here is the explaination for this.

So I was thinking If I would delete all fields which I am not using anymore, API would give me all active which I want to push using API.

  I am sure it is confusing do let me know if you need some more explanation in this.

Dony(D)