The UPI debit after an IPO allotment almost never fails. Your bid amount has been blocked in your bank account since you approved the mandate, so the money is already set aside when the debit happens. If the debit ever did fail, the allotted shares would not be transferred to your demat account.
Why does the debit on allotment almost never fail?
Your UPI mandate works at two points. When you apply, it blocks your bid amount. Once your shares are allotted, the Registrar and Transfer Agent (RTA) sends the allotment file to your bank, and the blocked amount is debited against it. Because that amount has been earmarked in your account the whole time, it is still there when the debit is made.
What happens if the debit does fail?
The shares are not transferred to your demat account.
You can track your application's overall status, including allotment, under IPOs > Applied on the Rupeezy app — see How do I check my IPO application status?
Things to keep in mind
- This is different from a mandate that never gets approved before the bidding window closes, which can cause the application itself to fail without any allotment — see Why was my IPO application rejected?
- It's also different from your mandate status merely looking stuck on Rupeezy before allotment — see Why is the IPO mandate status not updated on Rupeezy?