Stop typing the number your bank texts into every form
How to keep your phone number private in Nigeria. Why the NIN-linked line that gets your bank OTPs matters, and which number to give everyone else instead.
4 min read
The supermarket wanted your number for loyalty points and the estate gate wanted it in the visitor book. Both got the same eleven digits your bank sends your OTPs to. Neither will tell you where that page or that spreadsheet goes afterwards.
What your line is attached to
Your line is registered to your National Identification Number. Your bank has the same line on your account and on your BVN record, and sends your alerts and one-time codes to it. It's probably your WhatsApp number as well, and the recovery number on your email. For most of your accounts, that one line is how they decide you're you.
A phone number on its own can't empty an account. It is the first thing a fraudster needs, though, and the one you hand out most freely.
SIM swap
A SIM swap is someone getting a replacement SIM for your number from your network, by pretending to be you or by paying someone on the inside. Your SIM goes dead. Their phone starts receiving your texts, including the OTPs from your bank.
To pull it off they need your number and enough personal details to sound like you. The more places your number sits beside your full name and date of birth, the easier that part gets.
If your phone suddenly loses service while everyone around you has signal, treat it as a swap until you know otherwise. Call your bank from another phone and ask them to put a hold on the account, then call your network. A SIM PIN stops a thief from using your physical SIM in another phone. It does nothing against a swap done at the network's counter, because the replacement is a brand-new SIM.
On a calmer day, ask your bank whether it offers a hardware token or approvals inside its app for transfers. The fewer of your transfers that depend on an SMS alone, the less a swapped SIM is worth to whoever holds it.
Leaks
Every form you fill puts the number somewhere you can't see. A loyalty spreadsheet, a delivery app's database, an online shop's mailing tool, a sales rep's WhatsApp broadcast list. Any of those can be copied or sold, and there's no recalling a number once it's out.
Then the texts start. Promos you never signed up for, and calls from someone who says he's from your bank and wants you to read out the code that landed a minute ago. Your bank doesn't need you to read an OTP back to anyone. Hang up.
Loan apps add another route. Some lenders have messaged and called everyone in a borrower's contact list to shame them into paying. If someone who saved your number took one of those loans, your number can sit in a lender's files without you ever installing the app. You can't stop that. You can keep the bank line out of other people's phones by giving them a different number.
Give out a number that can take the hit
The cheapest fix is one more SIM. Keep the line your bank and BVN use private, and buy a second line for everything public. The second line is registered to your NIN as well, and the network can still tell it's you. What it protects is the bank line.
| Who's asking | What to give them |
|---|---|
| A buyer or seller on a marketplace | The platform's in-app chat first, then the second line once you've agreed on a deal |
| A delivery rider | The second line. A number that expires after one SMS code is no use to a rider standing outside your gate |
| A supermarket loyalty card or a raffle | The second line, or nothing. Ask whether it's required before you write anything |
| An online sign-up that texts a code once | A virtual number |
| Your bank and your email recovery settings | The private line, and nowhere else |
Anything public follows the same rule. A number in an Instagram bio or a Facebook listing gets copied by people you'll never meet. If your business needs a number customers can find, make it the second line, and print that one on the flyer.
If your WhatsApp runs on the bank line, Settings > Privacy lets you show your profile photo and last seen to contacts only. Silence unknown callers, under Settings > Privacy > Calls, stops numbers you haven't saved from ringing your phone, and their calls still show in your call list.
A virtual number covers one form at a time
An Awbit virtual number is for the sign-up form that wants an SMS code before it lets you in. The marketplace you'll use once, or the site that won't show you a price until it has your number. You pick the app and a country and pay from your wallet. The code shows on your order page, and your real line never goes into the form. Whether a platform accepts a number like this is down to its own terms, and checking them is on you.
The app still sees your device, your IP address, your email and any card you pay with. A virtual number keeps your phone number off its records and does nothing about the rest.
The number also goes back to the carrier when its short window closes, and we don't rent numbers by the day or week. Anything you'll need to log back into a year from now belongs on a number you own, which brings you back to the second SIM.
It does nothing for the bank line itself. If someone already has that number and enough of your details, a virtual number bought today won't stop them walking into a network office tomorrow and asking for your SIM.
