Input tax credit availment on self-assessment permitted, subject to reversal if supplier fails to pay tax. Substitution establishes entitlement to avail input tax credit on a self assessed basis, subject to prescribed conditions and restrictions, with the amount credited to the electronic credit ledger. Credit availed in respect of supplies where the supplier has not paid the tax must be reversed with applicable interest in the prescribed manner; if the supplier later pays the tax, the recipient may re avail the reversed credit as prescribed.