How to Change Mobile Number in Bank Account (2026)

"I have a new number and my bank OTPs still go to the old one." The fix: update the registered mobile number through your bank's net banking or app if you still have the old SIM, through the bank's ATM with your debit card, or at any branch with ID proof if the old SIM is lost. Then register UPI again with the new number. Do it quickly, because a phone number you no longer control is the key to your bank account.

This guide explains each route, what to do when the old SIM is gone, what happens to UPI, and the protections you are owed, as of October 2026. It complements our broader guide to bank KYC update, which covers address and document changes.

Why your registered mobile number matters so much

Your bank-registered number receives every transaction alert and every OTP. It is also what UPI apps use to identify you and bind your device. If it is out of date:

• you will not get debit alerts, so you may miss fraud, and RBI's customer-liability rules depend on how quickly you report it;
• you cannot reset your UPI PIN or log in to net banking;
• if your old number is reassigned, a stranger could receive your OTPs.

That last risk is real. Telecom operators can deactivate numbers after a period of no use and reassign them after a waiting period. Since April 2025, NPCI has required banks and UPI apps to check the Mobile Number Revocation List at least weekly and act on revoked numbers, which can deactivate UPI IDs linked to them.

Ways to change your number

Not every bank offers every route. Look for "Update contact details" or "Change mobile number" in net banking or the app's profile section.

Step by step

If you still have the old SIM

1. Log in to net banking or the bank's app and find the profile or service request section.
2. Choose "Update mobile number" and enter the new number.
3. Enter the OTPs sent to the old and new numbers, plus debit card details if asked.
4. Note the service request number and wait for the confirmation SMS on both numbers.
5. Keep the old SIM active until every bank, card, insurer and investment account has moved to the new number.

If you lost the old SIM or it is already disconnected

1. First, check if the old number can be recovered. If the SIM was lost or damaged, your telecom operator can issue a duplicate SIM on the same number with ID proof. That is often the quickest fix.
2. If not, go to the ATM route if your bank offers it: insert your card, enter the PIN, choose the registration or mobile update option and follow the prompts.
3. Or visit any branch with original ID (Aadhaar, PAN, passport or voter ID), a filled request form and your account details. Sign exactly as on bank records.
4. Ask for a written acknowledgement with the date.
5. If you suspect the number was taken over (sudden loss of signal, unexpected OTPs), tell the bank immediately to block online banking and UPI; see SIM swap fraud.

After the change

6. Register UPI again. Put the new SIM in the phone, open the UPI app, re-verify the device with the new number, link the bank account and set or reset your UPI PIN.
7. Update the number elsewhere: credit cards, demat and mutual fund accounts, insurance, EPFO, income tax portal and Aadhaar.
8. Check that alerts arrive by making a small transaction.

Your rights and the bank's duties

• RBI's KYC rules allow updates through registered email or mobile and through digital and non-digital channels, and banks must give you a way to update contact details.
• Banks must send transaction alerts. RBI's customer-liability framework requires banks to ask customers to register a mobile number for SMS alerts and to send alerts for electronic transactions. Without your current number, you lose that protection.
• Reporting speed decides liability. Under the current rules, you have zero liability for a third-party fraud reported within three working days. For electronic banking transactions at commercial banks from 1 January 2027, revised RBI directions extend this to five calendar days. See unauthorised transactions and zero liability.
• A complaint must be answered. If the bank delays your request without reason, you can escalate and, after 30 days, go to the RBI Ombudsman at cms.rbi.org.in.

Worked example: why the delay is costly

Rohit switched numbers in January but never updated his bank. In March, a fraudster made a ₹30,000 debit from his savings account through a third-party breach. Because alerts went to his old number, he noticed only on the 8th working day, when he checked his statement.

• Under the current rules, a third-party breach reported after 7 working days falls under the bank's board-approved policy, so the refund is uncertain.
• Had alerts reached him and he reported within 3 working days, his liability would have been ₹0.
• Had he reported on day 5, his liability would have been the lower of ₹30,000 and ₹10,000, so ₹10,000, and the bank would refund ₹20,000.

A five-minute number update would have protected the full ₹30,000.

Ready-to-copy request or complaint

Subject: Request to update registered mobile number

Dear Sir/Madam,

I request you to update the registered mobile number on my account
ending [last 4 digits] / Customer ID [number].

Old number: [old number] (no longer in use since [date] / SIM lost)
New number: [new number]

I submitted this request on [date] through [branch / ATM / net banking],
reference [number], but the change has not been made. Please update it and
confirm on the new number.

As my old number may be reassigned, please treat this as urgent and block
OTP delivery to the old number.

Name:
ID proof attached: [type]
Signature:

If there is no response within 30 days, escalate to the grievance redressal officer and then the RBI Ombudsman (cms.rbi.org.in, 14448).

What not to do

• Do not give your new number, OTP or Aadhaar details to callers offering to update your bank number for you. Banks do this only through their own channels.
• Do not surrender or let the old SIM lapse before moving all financial accounts.
• Do not use a family member's number as your bank-registered number unless the account is joint and you both agree; their phone will receive your OTPs.
• Do not ignore an unexpected OTP or "mobile number updated" SMS. Call your bank's official number immediately.
• Do not fill forms from links in SMS or WhatsApp claiming your number "must be updated to avoid blocking".

After the update

Expect a short cooling period on UPI and possibly on adding new payees after a number change; banks use it to block fraudsters who change numbers before draining accounts. Plan large payments a day ahead, or use NEFT. If UPI still does not work, see UPI not working. And if you are reorganising your accounts anyway, it is a good moment to check where your idle savings sit; an FD calculator shows what a separate fixed deposit would earn compared with leaving it in savings.

Key takeaways

• Change your bank-registered number through net banking or the app if you have the old SIM, or through the ATM or a branch if you do not.
• A duplicate SIM on the old number from your operator is often the fastest fix when a SIM is lost.
• Re-register UPI with the new number and expect about 24 hours of lower limits.
• Out-of-date numbers mean missed alerts, and late reporting can change who bears a fraud loss.
• Never let anyone update your number for you over a call or link.