Getting a new SIM card or switching to an eSIM is a common process today. However, many users notice that banking SMS alerts, OTP messages and even UPI apps stop working for some time after the SIM change. This is not a technical issue but a security rule designed to protect users from fraud.
Why SMS services stop working?
In India, telecom companies follow security rules set by the Telecom Regulatory Authority of India. According to these rules, SMS services related to banking and financial transactions are temporarily blocked for about 24 hours after a SIM swap, SIM replacement or eSIM activation.
During this time, you may not receive one-time passwords (OTPs) from your bank. SMS alerts for debit or credit transactions may also stop. This restriction usually ends automatically after 24 hours once the telecom system confirms that the SIM change was genuine.
How it affects UPI apps?
The SMS block can also affect UPI-based payment apps such as Google Pay, PhonePe and Paytm.
These apps need to send a verification SMS from your phone to confirm that the mobile number is active on your device. If SMS services are temporarily restricted after a SIM change, the app cannot complete this verification. Because of this, users may not be able to activate UPI, log in to their account, or make payments until the restriction ends.
Once SMS services start working again, you can simply open the app and complete the verification process.
Why this rule exists?
The 24-hour delay is meant to prevent SIM swap fraud, a type of cybercrime. In such cases, fraudsters manage to get a duplicate SIM linked to someone else’s phone number. Once they control the number, they can receive banking OTPs and access financial accounts.
By blocking SMS services for a short time after a SIM change, telecom operators create a safety window that makes it harder for criminals to misuse the number.
What users should do?
If you have recently changed your SIM card or switched to an eSIM, it is best to wait for 24 hours before trying to set up UPI apps or making banking transactions. After the waiting period, SMS services should start working normally.
Although this delay may feel inconvenient, it is an important step to keep your bank accounts and digital payments safe.