If someone's mobile phone is stolen or lost, they must block their UPI ID due to security reasons. Google Pay users can call 1-800-419-0157, while PhonePe users can call 0806–8727–374 and Paytm users can call 0120-4456-456. After verifying relevant information, customer care executives will block the ID. Paytm users can also submit details in 24x7 help section on website.