When Your Mobile Number Becomes Your Identity: A Wake-Up Call

Last Saturday, I was in for a surprise. My phone suddenly lost signal. I restarted it, switched SIM slots, moved to a different area, but the dreaded “No Service” message wouldn’t go away. I assumed it was a temporary network issue, but even after hours, I couldn’t connect. When I finally reached customer service, I was told my SIM might be damaged.

The whole experience was frustrating. But more than that, it was a wake-up call about how much of my life revolves around my mobile number. Our dependence on it has become so ingrained that one disruption sets off a chain of problems. It isn’t just about calls. It is about access to our money, our work and the services we use every day.

A single point of failure

In the early days of mobile phones, a number was just a way to reach someone. Today it has effectively become our identity. We use it to log in to email, make payments, book appointments and reach almost every service. That convenience has quietly turned the mobile number into a single point of failure. Here is what one weekend without a working SIM touched.

What stopped working

UPI has transformed payments in India. It is fast, convenient and accepted almost everywhere, from groceries to utility bills, and it is almost entirely tied to your mobile number. That weekend I needed to make an urgent payment. The UPI app detected the SIM problem and asked me to reactivate, which needed an SMS I could neither send nor receive. Debit card payments were off the table too, because they need an OTP by SMS. So was net banking, which asks for an OTP to the same number on top of the transaction password. I had a couple of Buy Now, Pay Later services, but they aren’t widely accepted, and not everyone has them. I was locked out of every ordinary way to pay.

For me, it was an inconvenience. For a small business owner who takes payments on UPI all day, the same failure could stop the business. UPI’s security features matter, because they prevent fraud. But what happens to people who lose access to their number, for a day or for good?

That same weekend I needed a doctor’s appointment. The clinic confirmed appointments only by calling the mobile number. With my number out of service, I missed the call, and there was no option to confirm by email or any other way.

Then there was work. Multi-factor authentication (MFA) protects accounts by asking for a second proof besides the password, often an OTP sent to your phone. That adds security and creates a dependency: if the number is lost or unreachable, you are locked out. I could get into my work email only because I had backup codes stored. Many people don’t, or don’t know how to use them.

The same dependency is what criminals exploit. In SIM swap fraud, someone convinces your mobile operator to move your number to a new SIM. Once they have your number, they receive your OTPs, and with them, your accounts.

The replacement SIM

When I finally got a replacement SIM, it was more than a day before everything worked again. Part of the reason is a rule meant to protect me. To fight SIM swap fraud, a replaced SIM has its SMS blocked for the first 24 hours. So the one thing UPI needed to reactivate, an SMS, was the one thing my new SIM was not allowed to receive.

Regulators have added other waits for the same reason. Since July this year, you cannot get a porting code for seven days after a SIM swap, so you can’t switch to another operator in a hurry either. Each wait makes sense on its own: speed is exactly what a fraudster needs. Together, they mean that a genuine customer whose SIM fails is locked out for as long as a fraudster would be.

Fast restoration, stronger verification

I don’t think the answer is to wait. The answer is to verify better. A restoration or a port should be done within ten minutes, at any hour, but only after strong proof that the person asking really owns the number, such as biometric verification, instead of a waiting period that punishes the genuine customer along with the fraudster.

Mobile operators carry a large part of this responsibility. When I reached customer care, the help was slow. When a SIM fails, operators could step in quickly, with temporary access to the number or another way to verify.

But they are not the only ones. Every service that relies on the mobile number should ask: what happens if this number fails? Banks, payment apps and employers should offer alternatives to the SMS OTP, such as app-based verification, email or biometrics, and let users choose how they receive important information. Regulators could make such alternatives mandatory. No single method is safe on its own, and each brings its own trade-off between security and convenience, which is exactly why no one should depend on just one.

Beyond the mobile number

My weekend was more than a frustrating inconvenience. It showed how much we have staked on a single number: our money, our health appointments and our work all depend on one SIM card. In a world where everything hinges on that one number, we can’t afford to ignore the risk any longer.