Is it possible to add CRM Activities for Suppliers (P01301)

Is it possible to add CRM Activities for Suppliers in Application P01301 ?

If we try to add an Activity and use a Supplier No. in the Customer (Associations) field we get the following error:

Customer Not Found

CAUSE: No customer number was found on the business unit (job)

or workorder. )

RESOLUTION: The customer number must be updated on all workfile transactions

the system needs to invoice. Add a valid customer number to the business

unit (job) or work order or change the workfile transaction to a business

unit or work order that has a customer number attached. Remember to re-extend