How to Change Your Bank Details After Losing a Phone

Losing a phone can create an urgent banking risk, especially when your bank app, SMS alerts, email and mobile number are all connected to the device. The safest response is to secure access first, then change or restore the details linked to your account through an official channel.

In this guide, “bank details” may refer to your registered phone number, email address, residential address or other customer information. It does not mean changing your account number. If you only lost the handset but still control your SIM, your first priority is to block the device and protect your banking apps. If the SIM was also lost, contact your network provider quickly and ask for a replacement SIM with the same number.

Act immediately after losing the phone

Do not wait until you are certain that the phone cannot be recovered. Anyone who obtains an unlocked phone may be able to access saved messages, email accounts, banking apps or authentication notifications.

1. Call your mobile network provider. Ask the provider to suspend the lost SIM. This helps prevent unauthorised calls, texts and one-time passwords from reaching the person who has the SIM.
2. Contact your bank through an official channel. Use the number on the bank’s official website, your bank card or a verified statement. Explain that your phone is missing and ask the bank to restrict mobile banking, digital banking or card transactions if necessary.
3. Lock the phone remotely. Android users can use Google’s device-management tools, while iPhone users can use Apple’s Find My service. Lock the device, display a contact message if appropriate and erase it remotely if recovery is unlikely.
4. Change important passwords. Start with your email account, then change your banking-app password or online-banking login if the bank permits it. Do not reuse an old password or a password used on social media.
5. Review your accounts for suspicious activity. Look for unfamiliar transfers, withdrawals, airtime purchases, card payments, new beneficiaries or password-reset messages.

Never give anyone your banking PIN, password, card number, CVV, recovery code or OTP while trying to recover the account. A person claiming to be a bank employee does not need your secret credentials to “help” you block a phone.

Decide what needs to be changed

Losing a phone does not automatically mean that every bank detail must be changed. The correct action depends on what happened.

What happened	Usually needed
Phone lost, SIM still with you	Lock the phone, secure banking apps and sign in on a replacement device only after checking the bank’s instructions.
Phone and SIM lost	Suspend the SIM, request a replacement with the same number and notify the bank that the device and SIM are missing.
Phone number no longer available	Ask the bank to update the registered number through its approved verification process.
Phone stolen and account activity looks suspicious	Request an urgent account review and temporary restrictions while investigating the transactions.
Email or address has also changed	Update each affected customer detail separately and ask which documents or verification steps are required.

If you can recover your original number through a SIM replacement, keeping the same number may be simpler because it remains connected to your bank alerts and other services. However, the bank may still require you to re-register the app or confirm the new device.

How to change your registered phone number or other details

Banks use different procedures. Some allow limited profile updates through an app or internet banking, while others require a branch visit, customer-service verification or an approved short-code channel. Do not assume that a process used by one Nigerian bank applies to another.

Option 1: Restore your number with a replacement SIM

If you still want to use the same number, visit your network provider’s authorised service centre with the identification it requests. Ask for a SIM replacement or SIM-swap service. After the number is restored, contact your bank and ask whether you need to reactivate mobile banking, register the replacement device or remove the old device from your profile.

Do not hand your phone to an informal agent for banking-app activation. Complete sensitive steps yourself and check every confirmation message carefully.

Option 2: Update the number through the bank

If you have a new number, ask the bank how to replace the old registered number. The bank may direct you to a branch or another approved channel. Be prepared to provide identity information and answer account-verification questions, but only through a channel you independently confirmed.

Before leaving the branch or ending the call, confirm which services have been updated. Your new number may need to be connected separately to:

• transaction alerts;
• mobile and internet banking;
• card-not-present or online-payment notifications;
• password-reset messages;
• USSD or other mobile-banking services; and
• security notifications and fraud alerts.

Ask when the change becomes active and whether transactions will be temporarily restricted. If the bank sends a confirmation message, read it carefully and report anything you did not request.

Option 3: Update details at a branch

A branch may be the most practical route when you cannot access the old number, cannot log in to the banking app or suspect that someone accessed the phone. Carry the identification and account information the bank normally requires, but do not write your PIN or password on a form or show them to another person.

Explain the full situation clearly: when the phone was lost, whether the SIM was recovered, whether the phone was unlocked and whether you noticed any unauthorised activity. This helps the bank decide whether to block digital access, replace a card, reset a channel or investigate a transaction.

Secure the replacement phone

Once your bank confirms that access can be restored, set up the replacement phone carefully.

• Install the banking app only from the official app store or the bank’s verified website.
• Use a strong screen lock, preferably a long passcode rather than an easy-to-guess pattern.
• Turn on biometric protection where appropriate, but keep a secure passcode as a backup.
• Update the phone’s operating system and the banking app.
• Do not save your PIN, password or card details in an unsecured notes app.
• Enable transaction notifications and review them regularly.
• Remove the lost phone from the bank’s list of trusted or registered devices if that feature is available.

Also secure the email account connected to your bank. An attacker who controls your email may attempt password resets even after the SIM has been blocked. Review recovery numbers, active sessions and unfamiliar devices.

Warning signs of a scam during recovery

Phone loss creates a good opportunity for impersonators. Fraudsters may call or send a message claiming that they can restore your account, reverse a transfer or complete a SIM replacement. They may ask you to read out an OTP, dial a code, install a remote-access app or transfer money to a “safe” account.

End the conversation and contact the bank yourself using a verified number. Do not click links in unexpected messages. Treat urgent threats, requests for secrecy and promises of instant recovery as warning signs.

If money has already left the account

Report the transaction to the bank immediately and request a reference number. Ask whether the bank can place restrictions on the affected channel, card or beneficiary while it investigates. Record the date, amount, transaction reference and the steps you have taken. If the phone was stolen, report the theft to the appropriate authorities and keep the report details.

There is no guarantee that a disputed transaction will be reversed, so speed matters. Do not wait for the replacement phone before reporting suspicious activity.

A simple recovery order to remember

Block the SIM, notify the bank, lock the phone, secure your email, verify transactions, then update or restore your bank details. Use only official bank and network-provider channels, and keep every secret credential private. For Nigerians who rely on mobile banking for bills, transfers, work and online services, this order can reduce the damage caused by a lost phone and make it easier to regain safe access.