Challan generation: mandatory online challan triggers bank confirmation and credit to the taxpayer electronic cash ledger. Challan payments must be generated online in FORM GST PMT-06; manual challans are prohibited. A CPIN is issued on generation and, upon bank realisation, a CIN is issued to evidence credit to the government account and trigger credit to the taxpayer's electronic cash ledger. E-FPB branches of authorised banks collect payments and maintain segregated government accounts. Where bank communication fails, taxpayers may use FORM GST PMT-07 or rely on RBI e-Scrolls for electronic cash ledger updates; discrepancies are reported via FORM GST PMT-04. Unique IDs track each ledger debit or credit and liability entries.