SIM: When many people buy a new SIM, change the SIM, or shift to eSIM, they feel that the biggest problem is the network or activation time.

(Be careful if you have taken an e-SIM)

SIM: Many people, when purchasing a new SIM, changing their SIM, or switching to an eSIM, assume the biggest issue is network connectivity or activation time. However, the real problem is often the temporary suspension of certain services. This suspension is typically for 24 hours and is intended to prevent online fraud.

Under Indian telecom regulations, the Telecom Regulatory Authority of India (TRAI) has implemented certain security measures. These measures temporarily disable certain services after a SIM card replacement or eSIM transfer to prevent unauthorized access to your number.

SMS ban for 24 hours after SIM change

When a user inserts a new SIM, replaces a SIM, or transfers to an eSIM, telecom companies block SMS services for approximately 24 hours. SMS cannot be sent or received during this time.

This directly impacts banking and digital payment-related messages. For example, OTPs or payment notifications from banks may not be received for a period of time. Because most banking systems rely on SMS-based verification, many services are temporarily down during this period. SMS service automatically returns to normal after 24 hours.

There may be problems logging into UPI apps.

Unified Payments Interface (UPI) apps used for digital payments also rely on SMS verification. Therefore, it may be difficult to use these apps immediately after a SIM change.

For example, apps like Google Pay, PhonePe, and Paytm send SMS to verify device identity. If the SMS service is disabled, the app cannot be logged in or activated.

Once the 24-hour pause is over, users need to reopen the app and complete the verification process. After this, UPI services will resume functioning normally.

Impact on bank transactions and OTP

Banking services may be temporarily affected after a SIM change. During this time, you may not receive the OTP required for card payments, fund transfers, or internet banking logins. SMS alerts related to bank deposits or withdrawals may also be temporarily disabled. However, some banks offer email OTPs or other security options that may work during this time.

What to do if you have changed your mobile number?

If you've changed not just your SIM but also your mobile number, there are some additional steps required to reactivate your bank and UPI services. First, you need to update your new mobile number through your bank or through an official process. Next, you need to re-register your UPI ID with the new number, as the UPI ID associated with the old number will no longer be valid.

How this rule protects against fraud

The main reason for temporarily disabling SMS services after a SIM card change is to prevent SIM swap fraud. Sometimes, fraudsters obtain duplicate SIM cards for someone's number and then attempt to access bank accounts using OTP.

This 24-hour freeze serves as an additional layer of security in such cases. It prevents fraudsters from immediately obtaining the OTP and gives the genuine user time to immediately notify the telecom company or bank if any suspicious activity occurs with their number.