Input tax credit requires possession of a tax invoice and receipt of supplies, subject to payment and return conditions. Eligibility for input tax credit requires a registered person to have a tax invoice or prescribed document from a registered supplier, actual receipt of goods or services (including delivery to a third party on the recipient's direction), actual payment of the tax to the Government (in cash or by admissible credit), and furnishing of the return under section 39. Credit for goods received in instalments is allowed only after the final instalment, and claims are time barred after the due return for the specified post year month or the annual return, whichever is earlier.