The return is not considered as a valid return.
The return furnished by a taxable person shall not be treated as valid return unless the full tax due as per the said return has been paid. It is only the valid return that would be used for allowing input tax credit (ITC) to the recipient.
Penal consequences to recipient of goods / service:
In other words, unless the supplier has paid the entire self-assessed tax and filed his return and the recipient has filed his return, the ITC of the recipient would not be confirmed.
Penal consequences to supplier of goods / service:
A taxable person who has not furnished a valid return shall not be allowed to utilize such credit till he discharges his self-assessed tax liability.