Dial `*#21#` to check unconditional call forwarding
Dial `*#61#` to check forwarding when unanswered
Dial `*#62#` to check forwarding when unreachable
Dial `*#67#` to check forwarding when busy
Check your phone’s Call Forwarding settings in the Phone app
On iPhone, go to Settings > Phone > Call Forwarding
On Android, open Phone app > Settings > Calling accounts or Supplementary services > Call forwarding
Look for a forwarding number or an enabled status
Contact your carrier if the codes or settings do not show the status