Some carriers let you dial these codes to see if call forwarding is enabled and which number your phone is currently forwarding calls to — either when you’re busy (*#67#) or for all calls (*#21#). You can change it to forward calls to another number, such as your home, office, or a third-party answering service, in settings.
On iPhone, to change the forwarding number, go to Settings > Phone > Call Forwarding. On Android, the steps vary, but generally you’ll open the Phone app, tap the three-dot menu, go to Settings > Calling accounts, select your active SIM, and then look for the call forwarding option.
If you see “Failed/Error” instead of “Enabled/Disabled” displayed after entering these codes — and you don’t see call forwarding in your settings — it likely means your carrier doesn’t support the feature on your plan.
