SIM Swap Fraud: When Losing Signal Means You Are Being Robbed

If your phone suddenly shows "No Service" or "Emergency Calls Only" and you have not moved, dropped your phone, or missed a bill payment, stop what you are doing. This is very likely SIM swap fraud or call forwarding fraud — someone has taken over your mobile number, either by getting a duplicate SIM issued in your name, or by tricking you into dialling a code that forwards your calls and OTPs to them. The moment signal drops for no reason, call your bank's fraud helpline from another phone and contact your telecom operator's customer care immediately. Every minute your number sits in someone else's hands is a minute they can use your OTPs to move your money. SIM swap fraud is frightening because the first sign is not a suspicious message — it is silence.

What SIM swap fraud actually is

Your SIM card is the small chip that proves to your telecom network that a phone number belongs to you. Every bank account, UPI app, and email linked to that number treats a call or SMS to it as proof it is really you. SIM swap fraud is when a criminal convinces your telecom operator to move your number onto a new SIM they control — or tricks you into forwarding your own calls to a number they own. Either way, your phone goes silent, and their phone starts receiving your OTPs, bank alerts, and calls.

How the scam actually works

Scammers do not start with your SIM. They start by collecting your personal details — from data leaks, phishing messages, fake job or loan forms, or a call pretending to be your telecom operator or bank — going after your name, number, date of birth, and the last four digits of your Aadhaar or a similar ID.

A typical version goes like this. There are two common routes attackers use:

Route one — the duplicate SIM. Using your details, the scammer approaches a telecom retail outlet or uses a forged document, claiming your SIM is "damaged" or "lost," and requests a replacement in your number. Once staff approve it — meant to require identity verification, but fraudulent documents and careless retailers have made it possible in real cases — your original SIM stops working the moment the new one activates. You lose signal; they gain your number.

Route two — call forwarding by trickery. Here the scammer never touches your SIM. They call pretending to be your telecom provider, a courier, or "customer support" and walk you through dialling a short code — something that sounds routine, like "confirming your KYC." What that code actually does is enable unconditional call forwarding, silently sending all incoming calls, including OTP calls, to a number they control. Your signal usually stays intact here, which makes it dangerous in a different way — you may not notice anything is wrong until money is already gone.

Either way, the endgame is identical: with your number under their control, the scammer resets your bank, UPI, or email password using "forgot password," receives the OTP only you should get, and logs in as you — then moves money out, often across several accounts, before you can react.

physically removed by you — treat it as a live emergency, not a technical glitch. Call your bank's fraud number from a different phone or landline immediately, even before you figure out what happened.

The red flags

You usually get warning signs before the takeover, if you know what to look for.

forwarding code to "protect," "verify," or "upgrade" your SIM. If anyone asks you to do this, hang up and call your operator back using the number printed on your bill or their official app — never the number that just called you.

If it is happening right now

If your phone has genuinely lost signal without explanation, or you already dialled a code someone told you to and now suspect something is wrong, act in this order:

1. Do not wait to "see if it comes back." Move immediately to a family member's phone or a

1. Call your bank's official fraud helpline (the number on the back of your card) and ask them to

1. Call your telecom operator's customer care from another number and report that your SIM may

1. If you dialled a call-forwarding code by mistake, dial ##002# the moment you regain signal —

1. Do not enter any OTP, PIN, or password into any link or call you receive during this window,

If you have already paid or lost money

Speed decides whether you get your money back. Every hour matters.

1. Call 1930, the National Cyber Crime Helpline, immediately — the fastest route to get a fraud

1. File a complaint at cybercrime.gov.in, the government's National

1. Call your bank directly and ask them to freeze the account and raise a formal dispute or

1. Preserve evidence: screenshots of the fraudulent SMS, the SIM swap or port confirmation

1. Secure every account linked to that number — email, UPI, net banking, social media — once your

Under the Reserve Bank of India's Customer Liability Framework, a customer who reports an unauthorised electronic transaction within three working days of notification can claim zero liability, meaning the bank must credit the disputed amount, subject to RBI's conditions (RBI, "Customer Protection – Limiting Liability of Customers in Unauthorised Electronic Banking Transactions," 2017). This is exactly why reporting fast, not staying quiet out of embarrassment, protects your money.

anything happens. In a panic, searching for the right number wastes precious minutes.

How to check and stop unauthorised connections — Sanchar Saathi

The Department of Telecommunications runs Sanchar Saathi, a portal and app that lets you see every mobile connection active in your name across all telecom operators, and report ones you did not take — it will get a fraudulent connection disconnected. It is also where you report a lost or stolen phone for blocking, and flag suspicious calls and SMS through its Chakshu feature. Checking Sanchar Saathi every few months, the same way you'd check a bank statement, is one of the few genuinely useful preventive habits against SIM-related fraud.

How to protect family, especially elderly parents

Elderly parents and anyone less familiar with phones are more likely to be talked through a "verification" call step by step, including dialling a forwarding code, because the caller sounds patient and official. Sit with them once and do the following:

1. Save your own number and 1930 as an emergency contact they can reach from any phone.
2. Tell them plainly: no one from the phone company or bank will ever ask them to read an OTP aloud or

1. Show them what "No Service" looks like and tell them to call you immediately if it happens without

1. Check the family's connections together on Sanchar Saathi every few months.
2. Agree that any "urgent" request about their SIM or bank account gets a call to you first.

Bachao.AI, built by Dhisattva AI Pvt Ltd, publishes research like this to help ordinary Indians recognise scams before they lose money — the fastest way to stop a SIM swap is recognising it in the first sixty seconds, not after the damage is done.

Frequently asked questions