Letter To Bank For Mobile Number Update

When and how to use this letter

Mobile number changes are sensitive, so banks verify them carefully — expect to visit the branch with your ID proof and possibly your old SIM or a signed declaration. The update usually takes 24 to 48 hours to reflect across all services. Until it is active, OTP-based logins and payments may fail, so do not start the change right before a payment deadline.

Many banks now allow mobile number updates through the app or internet banking with OTP verification on both numbers. If you still have access to the old number, this is the fastest route. If you have lost the old SIM entirely, the branch route with ID verification is mandatory.

After the update, test it immediately: log in to your banking app and request a test OTP. Also update the number linked to your debit and credit cards separately if your bank maintains card-level records. Keep the acknowledgment receipt until all alerts arrive on the new number.

If alerts still go to the old number after 48 hours, return to the branch with your acknowledgment — the update may have applied to the account but not to the card or alert services. Also re-register your number for any SMS-based services like balance inquiry codes. Never share the OTPs you receive during the process with anyone claiming to be from the bank — bank staff never ask for OTPs.

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