You can pay stamp duty for off-market or invocation transactions directly to CDSL using its SEBI-verified valid UPI handle via QR code or UPI ID.

Steps to pay stamp duty:

1. Visit www.cdslindia.com → Quick Links → Stamp Duty → Stamp Duty Payment.
2. Select Entity Type: Beneficial Owner (BO) 
3. Enter the following details:
   1. BOID (Demat Account Number)
   2. Mobile number
   3. Email ID
   4. Stamp duty amount
   5. Captcha (BO name auto-displays for confirmation).
4. Click Proceed for Payment.
5. Choose Pay by QR (scan the QR) or Pay by VPA (enter and verify your UPI ID).
6. An Order ID will be generated, and a payment request will be sent from CDSL’s valid UPI handle cdsl.stamp.dep@validhdfc.
7. Approve the request in your UPI app. On successful payment, confirmation will be shown and emailed to you.

Ensure payment is made only to the CDSL valid/verified UPI handle to avoid delays.