SIM Swap Bank Fraud
Fraudsters get a duplicate SIM issued for your number, receive your bank OTPs and drain your account. A sudden loss of signal is the first sign.
Your phone suddenly shows no network for hours, and a few minutes later your bank account is empty. In a SIM swap, a fraudster gets a new SIM issued for your number, so every call and OTP comes to them instead of you. Banks send OTPs to your registered number, so whoever holds the SIM can approve transfers if they also know your banking details.
How the scam works
The fraudster first collects your personal details through phishing links, fake KYC calls, leaked data or a chat in which you shared your name, date of birth and address. They may also gather your bank login details through a lookalike page. None of this is enough alone, because the OTP still goes to your SIM, so the next step is to take your number.
They then ask the mobile operator for a duplicate SIM using forged documents or a fake letter, or they trick you into sharing a code that approves a SIM upgrade. Some call you as 'network staff' saying your SIM must be upgraded and ask you to press a key or send a message. When it works, your own SIM goes dead and the new one becomes active for them.
With your number in hand, they log in to your net banking or UPI using the details they already collected, receive every OTP and move the money out in a few quick transfers. They may also reset your passwords and set up new payees. They usually act at night or on a holiday when you are less likely to notice a signal loss or call your bank.
An example of what you may see
Example only: 'Dear customer, this is the network desk. Your 4G SIM must be upgraded to 5G today or it will be blocked. Please reply with the code you will receive and press 1 to confirm the upgrade. Do not switch off your phone. If you do not confirm in 30 minutes, your number will be disconnected.' Soon after, your phone loses signal and stays without a network. The caller sounds calm and keeps repeating that you must not call anyone else.
This example is written for illustration. Real messages change their wording, names and links all the time.
Red flags
- Your phone loses network for a long time without a reason.
- A caller asks you to press a key or share a code for a SIM upgrade.
- You get bank alerts about password or number changes you did not make.
- A message about a new SIM request arrives that you did not ask for.
- Your calls and messages stop but other phones in the house are fine.
- A caller already knows many personal details and asks for more.
What to do right now
- Never share a code or press a key for a SIM upgrade on a call.
- If your signal drops, use another phone to call your operator on the number on your bill.
- Call your bank from another phone and ask to block net banking and UPI.
- Check your bank alerts and email for changes you did not make.
- Set a SIM lock or PIN if your operator offers one.
If you already paid or shared a code
- Call 1930 quickly from another phone and give the details and time.
- Call your bank on the number printed on your card and block accounts, cards and UPI.
- Ask your operator to block the duplicate SIM and issue a new one after identity checks.
- Report at https://cybercrime.gov.in and change all banking passwords.
National Cyber Crime Helpline: 1930. Report online at cybercrime.gov.in. Do it fast: the sooner your bank is told, the better the chance that money can be held.
Where this scam shows up
Read how it looks on each channel:
How Safeavio helps
Safeavio includes a SIM-change alert for the anti-theft feature, which can tell the owner through the portal that the SIM in a protected phone has changed. That helps for a lost or stolen phone, but it cannot see a swap done by the operator on your number. Pay attention to a sudden loss of signal and call your bank from another phone.
Check it before you tap or pay
Safeavio Sentinel is a made-in-India Android app: paste a message or link, or scan a QR code, and get a plain verdict with the reasons. It helps you spot a scam; it does not promise to stop every one.
Download for AndroidWhat the app does
Google Play listing: coming soon. Today the signed APK is on safeavio.com/download. Android 7.0 or later.
Questions people ask
What is the first sign of a SIM swap?
Usually a sudden and long loss of mobile network on your phone while other devices around you work. If that happens, call your operator and bank from another phone as soon as you can, especially if it happens near bank alerts.
Can a fraudster swap my SIM without my phone?
Yes. They can request a duplicate SIM from the operator with forged papers or by tricking you, and then your number works on their SIM. That is why you should never share codes during a SIM upgrade call.
How can I protect my number?
Do not share personal details with callers, keep your documents safe, use strong banking passwords and ask your operator about extra protection. Check your bank alerts and tell your bank at once if your signal disappears.