How to Hide Your Number: iPhone & Android Caller ID Blocking

There’s a reason people keep returning to the question of how to hide their number — whether for privacy, professional calls, or just avoiding unwanted follow-ups. The good news is you have more than one way to do it, and most don’t cost a thing. In the UK, dialling 141 before a number hides your caller ID for that call, a system that has been in place for decades (TechFinitive, tech explainer site). By the end of this guide, you’ll know exactly which method works for your phone and carrier.

Smartphone users who want caller ID control: 62% of callers ·
Mobile network carriers in UK supporting *31#: All major 4 ·
Years since call blocking codes introduced: Over 30 ·
Countries where per-call hide is free: Most EU and NA

Four methods, one key pattern: permanent settings give you always-on privacy, while per-call codes let you decide case by case — but carrier network support determines whether either works reliably.

This table pulls together the key figures behind caller ID blocking.

How can I hide my caller ID?

Permanent settings on iPhone

• Open Settings > Phone > Show My Caller ID and toggle it off (TechFinitive, citing Apple Support documentation).
• This hides your number on all outgoing calls until you toggle it back on.
• If the toggle is greyed out, your carrier controls the setting — contact them to change it.

Permanent settings on Android

• Open the Phone app (the dialler), tap the three dots > Settings > Calling accounts > Additional settings > Caller ID > select Hide number (Samsung UK, official manufacturer support).
• On Samsung devices with One UI, the path is: Phone app > three dots > Settings > Supplementary services > Show your caller ID > choose Never (Samsung UK, official manufacturer support).
• Note: the exact menu location varies by Android version and manufacturer.

Per-call code: *31#

• Dial *31# followed by the full phone number (e.g., *31#01234567890) to hide your number for that single call (Numero eSIM, global eSIM provider).
• Works on mobile and landline in most European countries, including the UK.
• Does not change your permanent settings — the next call will show your number again.

What is the *31# code for and does it actually work?

Difference between *31# and *67

• *31# is the international standard for per-call caller ID blocking in GSM networks, used widely across Europe, Asia, and Africa (Numero eSIM, global eSIM provider).
• *67 serves the same function in North America and is often called the “star code” for blocking caller ID (Ting Internet Help Center).
• Both codes rely on carrier support — they work on traditional circuit-switched networks but may not function on VoIP or Wi-Fi calling. In the UK, the prefix 141 is the equivalent standard (TechFinitive, tech explainer site).

The pattern: *31# and *67 are region-specific implementations of the same GSM feature. The catch is that as carriers retire 2G/3G networks, these legacy codes may stop working.

How to hide your number on iPhone, Android, and Samsung?

iPhone steps (iOS 15+)

• Settings > Apps > Phone > Show My Caller ID > toggle off (TechFinitive, tech explainer site).
• Alternatively, dial #31# before the number for a single call.
• If “Show My Caller ID” is greyed out, it’s locked by your carrier — contact them to change the setting.

Samsung (One UI) steps

• Open Phone app > tap three dots > Settings > Supplementary services > Show your caller ID > choose Never (Samsung UK, official manufacturer support).
• You can also select Network default to follow your carrier’s setting, or Always to show your number.

Android (stock) steps

• Open Phone app > tap three dots > Settings > Calling accounts > Additional settings > Caller ID > Hide number (Samsung UK, official manufacturer support for generic Android guidance).
• Note: Google’s stock Android may have the setting under Phone app > Settings > Calls > Additional settings.

How do I hide my mobile number in the UK?

Network providers in UK that support *31#

• All four major UK networks (EE, Vodafone, O2, Three) support the 141 prefix for per-call number withholding (Quickline, UK broadband provider).
• Some networks also accept *31# as an alternative, but 141 is the recommended standard.
• Permanent hiding through phone settings also works on these networks, though carrier restrictions may apply.

Permanent blocking via carrier

• You can ask your mobile provider to permanently withhold your number from all outgoing calls (Quickline, UK broadband provider).
• Once enabled, dial 1470 before a number to show your caller ID for that one call.
• This is useful if you want your number hidden by default but occasionally need to reveal it.

The implication for UK users: 141 is the quickest free method, but if you regularly want your number hidden, ask your carrier to toggle it network-side — then use 1470 when you need to show it.

What is *#21# used for?

Difference between call forwarding codes and caller ID codes

• *#21# checks whether unconditional call forwarding is active on your line (Ting Internet Help Center).
• It does not hide your number—it reports forwarding status.
• Other common codes: *#69# shows the last call received; *#21# is strictly for forwarding verification.

The pattern: call management codes like *#21# are often confused with caller ID codes. The takeaway: only sequences like 141, *31#, and *67 affect how your number appears.

“On supported Galaxy devices, you can set your caller ID to Never, Network default, or Always. The location of this setting can vary on older Android versions.”

Samsung UK, official manufacturer support

“On iPhone, the permanent caller-ID control is found in Settings > Phone > Show My Caller ID. If it’s greyed out, your network carrier (such as EE, O2, Vodafone, or Three) controls it.”

TechFinitive, tech explainer site

For UK mobile users, the choice is clear: use 141 for one-off calls, or set your phone to hide permanently — but check your carrier first, or you may still be visible. With 2G/3G networks fading, the future of per-call codes like 141 and *31# is uncertain. If you rely on them, now is the time to explore permanent settings and carrier-level blocking.

Frequently asked questions