Why You Shouldn't Give Your Real Phone Number to Every App
Almost every app, shop and website now asks for a phone number "to verify it's you". It feels harmless, but your mobile number has quietly become one of the most sensitive pieces of personal data you have. Unlike an email address, most people keep the same number for years, and it's often tied to their bank, their messaging apps and their identity.
What your number reveals
- It links your accounts together. The same number on a dating app, a marketplace and a messaging app makes it easy to connect those profiles to one person.
- It ends up in data leaks. Customer databases leak regularly, and phone numbers are usually in them. Once leaked, a number is shared and sold for years.
- It attracts spam and scams. Leaked numbers feed spam calls, fake delivery texts and phishing messages.
- It can be a key to your accounts. If your number is used for password resets or SMS codes, anyone who takes over your number can take over those accounts too.
Where your real number belongs
Keep your real number for the accounts where long-term recovery really matters and where the provider already knows who you are. Your bank, your mobile carrier, government services, your main email account, and the messaging app your family uses. For those, stability matters more than privacy.
Where a separate number makes sense
- One-off sign-ups for a trial, a forum, a Wi-Fi hotspot or a coupon.
- Marketplaces and classifieds where strangers would otherwise see your number.
- Testing and development. Checking an app's sign-up flow without using staff members' personal phones.
- Keeping work and personal identities apart.
An important caveat
A temporary verification number is for receiving a code now. It isn't a number you can count on having later. If a service might ask you to verify the same number again, for example to reset a password, use a number you control long-term for that account. Also set up a non-SMS recovery method where you can. An authenticator app, a passkey or backup codes.
Other ways to protect your number
- Ask your carrier for a SIM PIN or port-out protection, which makes SIM-swap attacks harder.
- Hide your number in messaging apps' privacy settings (who can see it, who can find you by it).
- Remove your number from public profiles and old accounts you no longer use.
- Prefer authenticator apps or passkeys over SMS codes for important accounts.
How telly.cat fits in
telly.cat rents numbers for receiving a verification SMS for hundreds of services and countries. You pay per code, and if no code arrives you get your money back automatically. It's a simple way to keep your personal number out of sign-ups that don't need it. Pick a service and country to see current prices.
FAQ
Why is sharing my phone number risky?
It links your accounts, ends up in data leaks and spam lists, and can be used in SIM swap attacks.
Where should I use my real phone number?
For banking, your main email, government services and accounts you'll need to recover for years.