The *#21# "trick" is a USSD code you can dial on your phone to check the status of your call forwarding feature, specifically unconditional call forwarding.
Understanding Call Forwarding and *#21
Call forwarding allows you to redirect incoming calls to another number. There are different types of call forwarding:
- Unconditional Call Forwarding: All calls are forwarded immediately.
- Conditional Call Forwarding: Calls are forwarded only under certain conditions (e.g., when your phone is busy, unanswered, or unreachable).
The *#21# code specifically relates to unconditional call forwarding.
How *#21# Works
When you dial *#21# and press the call button, your phone sends a request to your mobile network operator. The network responds with information about the status of unconditional call forwarding.
- Call Forwarding is OFF: If your phone rings normally when someone calls you, it means unconditional call forwarding is likely off, and the code will confirm this. You'll either receive a message indicating call forwarding is disabled or no information at all.
- Call Forwarding is ON: If unconditional call forwarding is enabled, the response will typically show the number to which your calls are being forwarded.
Example Scenario
Let's say you suspect your calls are being forwarded without your knowledge. You can dial *#21# to check:
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Open your phone's dialer.
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Enter *#21#.
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Press the call button.
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Wait for the message to appear.
- If the message states "Call Forwarding Unconditional Disabled," then your calls are not being forwarded unconditionally.
- If the message states "Call Forwarding Unconditional Enabled" and displays a phone number, your calls are being forwarded to that number.
Important Considerations
- Network Dependent: The exact message displayed may vary depending on your mobile network operator.
- Unconditional Only: This code only checks unconditional call forwarding. It won't tell you if conditional call forwarding (e.g., when busy) is active.
- Security: While useful, *#21# is not a foolproof security measure. Malicious actors could use more sophisticated methods of call interception.
In summary, *#21# is a quick and easy way to check if your calls are being unconditionally forwarded. If your cell phone rings when someone calls you, this code will return no information to you (or tell you that call forwarding is off).
