Learn How to Block Your Caller ID on Calls

Understanding Caller ID Blocking: What It Is and How It Works

Caller ID blocking is a telephone feature that hides your phone number from appearing on someone else's phone when you call them. Instead of seeing your actual number, the recipient's phone typically displays "Unknown," "Private," "Blocked," or "Restricted" on their caller ID screen. This feature has been available since the 1980s and remains one of the most commonly used privacy tools in telecommunications.

When you block your caller ID, your number still connects to the other person's phone line—the call goes through normally. The only thing hidden is the identification information. The recipient can still answer the call and talk with you just as they would with any other incoming call. The blocking happens at the network level, meaning the telephone company processes your request before the call reaches the other person's device.

There are several reasons people use caller ID blocking. Some want privacy when calling businesses or services where they prefer not to share their number. Others block their ID when calling friends or family members who might screen calls. In workplace settings, employees may block their numbers when calling on behalf of their company rather than personally. Healthcare providers sometimes block their IDs to protect patient privacy, and researchers conducting surveys may block their numbers to reduce bias in responses.

According to the Federal Communications Commission (FCC), caller ID blocking is a standard feature offered by most phone carriers in the United States. The technology works with both landline and mobile phone systems, though the specific steps to activate it may differ depending on your phone type and service provider.

Practical Takeaway: Before learning how to block your caller ID, understand that this feature simply hides your phone number from the recipient's display while still allowing your call to connect normally. The call quality and connection remain unchanged.

Per-Call Blocking: The *67 Method and Its Limitations

The simplest way to block your caller ID on a single call is to use the *67 code before dialing. This method works on most phone systems in North America and is available regardless of your phone plan or carrier. To use per-call blocking, you dial *67, followed by the phone number you want to call. When the call connects, your number will not appear on the recipient's caller ID.

For example, if you want to call 555-123-4567 with your number blocked, you would dial *67-555-123-4567 (or *67 followed by a pause, then 555-123-4567, depending on your phone system). On some older phone systems, you might hear a brief tone or announcement confirming that your number is blocked before the call connects. The recipient will see your call as coming from a restricted or unknown number.

The *67 method has several important limitations to understand. First, it does not work on all phone systems or in all regions outside North America. Some international calling systems use different codes or do not support per-call blocking. Second, if you call a business that uses advanced call screening technology, blocking your number may cause your call to be rejected automatically. Many businesses now refuse calls from blocked numbers as a fraud prevention measure. Third, if the person you are calling has subscribed to a service that unblocks restricted numbers, they may still see your phone number despite your blocking attempt.

The *67 method also does not work when calling certain types of numbers. Emergency services (911), toll-free numbers (800, 888, 877, 866, and similar prefixes), and directory assistance lines typically do not allow caller ID blocking. If you attempt to use *67 before calling these services, your call will likely still reveal your number, or the call may not go through at all. Additionally, some private businesses and government agencies maintain caller ID unblocking technology that bypasses *67 blocking.

Practical Takeaway: The *67 code provides a quick, no-cost way to block your number on individual calls, but it does not work for emergency numbers, toll-free lines, or businesses using call-filtering technology. It is best suited for occasional, personal calls where you want temporary privacy.

Permanent Caller ID Blocking Through Your Phone Carrier

If you want to block your caller ID on all outgoing calls rather than using *67 each time, you can contact your phone carrier to set up permanent blocking. This service is typically called "Caller ID Blocking," "Anonymous Calling," or "Calling Line Identification Restriction" (CLIR) depending on your carrier. Most major carriers in the United States offer this service, including AT&T, Verizon, T-Mobile, and smaller regional providers.

To set up permanent blocking, contact your carrier's customer service department by phone, online chat, or through their mobile app. The process usually takes only a few minutes. Your carrier will ask you to confirm your account information and explain that you want all your outgoing calls to display as restricted or unknown. Some carriers charge a small monthly fee for this service, ranging from $2 to $5 per month, while others offer it for free as part of their standard calling features. You should ask about pricing when you contact them.

Once permanent caller ID blocking is activated on your account, every call you make will appear as restricted or unknown to the recipient, unless you temporarily unblock your number for a specific call. To temporarily unblock your number when you have permanent blocking enabled, dial *82 before the phone number. This "unblocks" your ID for just that one call, allowing your number to display normally. This is useful if you have permanent blocking but occasionally need your number to be visible—for example, if you are expecting a callback from a doctor's office or business and want them to have your number.

The disadvantages of permanent blocking include the same limitations as *67: emergency numbers will still display your number (or may not connect properly), toll-free lines may reject your calls, and businesses with unblocking technology may still see your information. Additionally, some people find it inconvenient to have their number blocked on all calls, especially if they frequently call businesses or services that need to return their calls later.

Practical Takeaway: Permanent carrier-based blocking hides your number on all calls unless you temporarily unblock it using *82. This option works best if you make most of your calls privately and only occasionally need your number to be visible.

Blocking Caller ID on Smartphones and Mobile Devices

Smartphone users have additional options for blocking caller ID beyond the standard *67 and *82 codes. Both iPhone and Android devices offer built-in settings that allow you to control how your number appears on outgoing calls. These settings work with your mobile carrier's network and provide a more integrated approach than manually entering codes for each call.

On iPhones, you can adjust your caller ID settings through the Phone app or in the device's main Settings menu. Navigate to Settings, select Phone, and look for an option labeled "Show My Caller ID," "Display as Anonymous," or "Hide My Number" depending on your iOS version. Toggle this setting off to hide your caller ID on all outgoing calls. You can turn this setting on and off as needed whenever you want to switch between showing and hiding your number. Some carriers also provide their own mobile apps that include caller ID blocking controls alongside other account management features.

Android devices similarly offer caller ID hiding options, though the exact location varies by manufacturer and operating system version. Most Android phones have a Phone app where you can access calling settings. Look for options related to caller ID, calling line identification, or privacy settings. The setting may be labeled "Hide Number," "Show Your Number," "Caller ID," or similar terms. Android also allows you to toggle this setting on and off as needed. Additionally, many Android users can access their carrier's separate app to manage caller ID settings alongside other account features.

When using smartphone settings to block caller ID, be aware that these settings typically apply only to calls made through your phone's native calling app. If you use third-party calling apps like Google Voice, WhatsApp, Skype, or other VoIP services, those apps may have separate caller ID settings that do not synchronize with your phone's main calling settings. Each app typically includes its own privacy or settings menu where you can configure how your number displays to recipients of calls made through that app.

Practical Takeaway: Smartphone settings for hiding caller ID are often more convenient than entering codes manually. Check your Phone app settings or your carrier's mobile app to find caller ID options, and remember that third-party calling apps have separate settings for caller ID display.

When Caller ID Blocking May Not Work or Is Not Recommended