Refund of IGST on export invoice mismatches: e-mailed concordance submission accepted as primary support for refund claims. Refund of IGST on exports with invoice mismatches will be processed through an alternate mechanism requiring exporters to e-mail a prescribed concordance table mapping GST invoices to shipping bill invoices to the designated Deputy Commissioner, Drawback, NS-II, JNCH; electronic submission is the primary support for refund claims and physical attendance is not required though optional in-person assistance is available.