Keeping your personal phone number private when you sign up online

Why it matters

Companies that collect your number can store it, share it with partners, and lose it in a data breach. Once it is out, it can be used for spam, scam calls and attempts to hijack your accounts through your carrier. Giving it to fewer places means fewer places to leak it.

Sensible habits

• Give your real number only to services that genuinely need it, such as your bank.
• For one-off sign-ups, use a separate number that can receive the verification code and nothing else.
• Turn on app-based or hardware two-factor authentication for important accounts instead of SMS where the service allows it.
• Review privacy settings on messaging apps so that your number is not visible to everyone.

Where a virtual number fits

A temporary virtual number is suited to low-stakes accounts where all you need is to receive a verification code once. For accounts you will rely on, such as banking or your main email, use a number you control permanently, because you will need to receive codes again.

What can go wrong when your number is everywhere

A phone number does more than reach you. It is often a login, a recovery method and a way to link your accounts across companies. The more places hold it, the more places can leak it, and the easier it is for someone to tie your accounts together. It is also the key to SIM-swap fraud, where a criminal persuades a carrier to move your number to a SIM they control and then uses it to reset passwords.

A privacy routine that is easy to keep

• Decide which accounts truly need your real number (bank, main email, government) and keep it for them only.
• Use a different method for everything else: an authenticator app for security, a temporary number for one-off verification.
• Ask your carrier to add a PIN or lock on SIM changes.
• Check app privacy settings for who can see your number or find you by it.
• Be cautious with forms that ask for a number you do not need. Leave optional fields empty.

Spotting scams that use your number

Never read a verification code to someone who contacts you. Real services do not ask for it. A message that says a code was sent to you and asks you to forward it is almost always an attempt to take over an account. If you receive a code you did not request, someone may be trying to sign in as you; change your password for that service.

Privacy is a habit, not a product

A virtual number reduces how many companies hold your real contact details. It does not replace good security. Combine it with unique passwords, a password manager and an authenticator app for the accounts that matter.