Image: NeuLex, Wikimedia Commons, CC BY-SA 3.0.
A SIM-swap scam happens when someone fraudulently gets a replacement SIM for your mobile number. If the replacement becomes active, calls and text messages may stop reaching your phone, while the criminal may receive one-time passwords and account alerts. India’s National Cyber Crime Reporting Portal describes SIM-swap fraud as a way to obtain OTPs used in financial transactions.
Warning signs to notice
- Your phone suddenly shows “No Service” or cannot make calls and send SMS, even where coverage is normally available.
- You receive an unexpected message about a SIM replacement, porting request or number change.
- Your bank or payment app reports a login, password reset or transaction you did not initiate.
- Contacts tell you they received unusual messages or calls from your number.
A network outage can also cause loss of service, so do not assume every interruption is fraud. If service remains unavailable or you receive a SIM-change alert you did not request, contact your mobile operator using its official app, website or published helpline.
Steps that can reduce the risk
- Keep your mobile account secure. Protect the email account and customer account linked to your number with a unique password and available two-step verification. Do not share OTPs, SIM PINs or account credentials with callers.
- Be careful with identity details. Avoid posting documents or personal details publicly. Do not send identity documents through an unsolicited message or call.
- Use app-based security where available. For important accounts, enable passkeys or authenticator-based verification if the provider supports them. Review recovery phone numbers and email addresses periodically.
- Set transaction alerts. Keep bank alerts enabled and promptly check transactions. Never reveal an OTP to someone claiming to “cancel” or “reverse” a transfer.
- Respond quickly to a suspected SIM takeover. Contact the telecom provider through an official channel and ask it to secure or suspend the affected SIM. Contact your bank using the number printed on your card or its official app if financial accounts may be exposed.
If money has been taken
Report suspected cyber financial fraud immediately by calling India’s national helpline 1930 and submit the complaint through the National Cyber Crime Reporting Portal. Keep transaction references and messages for the complaint. Report the SIM issue separately to your telecom provider. A report does not guarantee recovery, so contact the bank promptly as well.
Safety note: This is general awareness information, not personalised banking, legal or cybersecurity advice. Use verified contact details from official websites and apps.
