Purchase without bill/invoice

You should insist the supplier to issue GST invoice if the supplier is also a registered person.

@ jacinthamary , they charge some 100-200₹ extra on buying with bill.
if i give 200 extra for the goods, i will not be able to sale the goods in my whole life time since the market is very competitive & most of the other parties are buying without bill at a 200₹ lower price.
my business line runs on a NP of less than 1%, therefore 100-200 matters ALOT.
unless everyone in the market takes bill, it is not possible for one to compete.

Agree with you sir. But there is no other way. If you are a composite dealer and you sell B2C then you have a chance you no need to issue invoice to them.

I am regular registered taxpayer which do both B2B & B2C transactions.
since some goods are transported to/from outside states i had to take regular registration.

First of all since u are registered taxpayer, u have to abide by all provisions of law. Hence u should issue sales invoice as u are not a composite dealer. in respect of ur supplier u ask them to issue invoice so that u can avail ITC, otherwise u will have to discharge ur GST liabilities without taking the benefit of ITC. Despite ur request if ur supplier doesn't listen to u, collect substantial evidence and submit complaint against him in the Department.