How to block your number when calling

The fastest way to hide your number for a single call works on almost every US and Canadian carrier:

1. Dial *67.
2. Immediately follow it with the full number you're calling — no pause, no spaces. For example: *6718005551234.
3. Press call.

The person you're calling sees Private, Blocked, No Caller ID, or Unknown instead of your number. It only applies to that one call — your next call shows your number normally again. Outside North America the code is often #31# instead of *67.

If you want your number hidden on every call, iPhone has a system setting:

1. Open Settings → Phone → Show My Caller ID.
2. Switch Show My Caller ID off.

Every outgoing call now hides your number until you turn it back on. Note: on some carriers this toggle is greyed out or missing — that means caller-ID blocking is managed on the carrier's side instead, so you'll need to use *67 per call or ask the carrier to enable line blocking (below).

On Samsung and most Android phones:

1. Open the Phone app.
2. Tap the ⋮ menu → Settings.
3. Tap Supplementary services (or Call settings → Additional settings on older devices) → Show your caller ID.
4. Choose Hide number (some phones phrase it 'Never show').

As on iPhone, the option's exact name varies by manufacturer, and if the setting is locked it's being controlled by your carrier.

Every major US carrier can hide your caller ID on every call at the account level — this is called per-line blocking and it's free:

• Verizon, AT&T, T-Mobile, and most carriers — call the carrier or ask in their app to enable 'Caller ID blocking' or 'per-line blocking' on your number.

With line blocking on, here's the twist: to show your number for one call (say, calling a business that rejects blocked calls), you dial *82 before the number — the opposite of *67. So *82 temporarily reveals a permanently-blocked number, and *67 temporarily blocks a normally-visible one.

To make your number visible again:

• If you dialed the per-call code: nothing to undo — *67 only affects that one call.
• On iPhone: turn Settings → Phone → Show My Caller ID back on.
• On Android: set Show your caller ID back to Show number.
• If your carrier line-blocks every call: dial *82 before a number to reveal your ID for that single call, or contact the carrier to remove per-line blocking entirely.

Also worth knowing: hiding your caller ID doesn't work when calling toll-free (800/888/etc.) numbers or emergency services — those can always see the calling number, and many businesses auto-reject 'No Caller ID' calls, so a blocked call may not get through at all.