Products must be assigned to customer , territory wise

Territory = Miami
Customer =David
sale invoice for products

another customer =Jhon
in same Territory =Miami
erpnext must not create sale invoice of the products already sold to Mr David

means , products must be assigned to customer , territory wise.

is it possible in erpnext , if yes …how?

Mr. Saif, there is nothing called ‘Product’ in ERPNext. It’s called ‘Item’ here. If you use appropriate terminology, it is much better for everyone.

If there is no stock of product, it will stop you from creating an Invoice.

You may attach default customer to Item in ERPNext, but this does not restrict in making a Sales Invoice for another customer.