What does pressing *#21 do on iPhone? The truth behind this mysterious code
Pressing *#21# on an iPhone displays your call forwarding status, not a secret diagnostic menu or hidden feature. This code, part of the GSM standard, shows whether your calls are being redirected to another number and where they're being sent.
Understanding the *#21# code: What it actually does
When you dial *#21# on your iPhone and press call, your device contacts your carrier's network to retrieve call forwarding information. The network responds with a simple display showing whether call forwarding is active and, if so, which number is receiving your forwarded calls. This isn't some secret iPhone feature—it's a standard GSM protocol that works across most mobile networks worldwide.
