intra state supply as inter state supply

GSTR 3B is a supplementary return which enables the government to collect revenue on time.

GSTR 1,2 and 3 should supersede 3B.

Facility to upload data for GSTR 1 has already started. Good news is that Details already submitted in 3B can be amended/deleted in GSTR 1.

Best and safest course of action will be to file 3B, make payment and use the balance in cash ledger in the future period.

If your amount is big you can take the risk of non-filing 3B. The maximum penalty for not filing is Rs. 5000/-