Unified Payments Interface (UPI) adoption enables app/web public issue applications with mandate-based fund blocking and electronic reconciliation. Permits application to public issues of debt, preference and securitised instruments via stock-exchange app/web interfaces and intermediaries with blocking of application funds through the Unified Payments Interface (UPI). Stock exchanges and depositories must validate PAN and demat details in near real time and transmit bid and UPI ID data to a designated Sponsor Bank, which initiates a one-time mandate for investor authorization. Upon mandate acceptance banks block funds and communicate status to Sponsor Bank, stock exchange and registrar; registrar reconciles block confirmations, prepares basis of allotment, and triggers debit/collect and unblocking actions for final settlement and allotment.