Hey Hmmmmmmmmmmmmm44,
We'd recommend reviewing this article for information on how call forwarding works with iPhone: Set up call forwarding and call waiting on iPhone - Apple Support
If you're seeing an issue with calls failing, we'd recommend: If you can't make or receive calls on your iPhone - Apple Support
"Contact your carrier
When you contact your carrier, make sure that:
- Your account is set up to use your iPhone.
- There aren't any localized service outages.
- Your account doesn't have a billing-related block.
- Your calls don't have errors on the carrier system.
Update your software
- Check for a carrier settings update.
- Check for an iOS software update. Some updates might require a Wi-Fi connection.
Check your settings
If you can't make or receive calls on your iPhone, follow these steps, testing after each step.
Check your network setings
- Reset your network settings. Go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. This will erase all current saved settings, including Wi-Fi passwords, preferred networks, and VPN settings.
- Try to make or receive calls in another location.
Check your iPhone settings
- Turn Airplane Mode on and off. Go to Settings and turn on Airplane Mode, wait five seconds, then turn it off.
- Check Do Not Disturb. Go to Settings > Focus > Do Not Disturb and make sure it's off. Learn how to use Focus on your iPhone or iPad.
- Check for any blocked phone numbers. Go to Settings > Phone > Blocked Contacts.
- Check Call Forwarding. Go to Settings > Phone > Call Forwarding and make sure it's off.
- Check Silence Unknown Callers. Go to Settings > Phone > Silence Unknown Callers. If the setting is on, a caller must be listed in your Contacts or Recents. Or they must have shared their number in Mail or sent you a message using that number in order for their call to go through. Add their number to Contacts to ensure the phone rings. Calls from some third-party apps might not go through.
To avoid missing calls from a contact, add their number to Contacts to ensure that your phone rings.
Learn more
Thanks!