How to set up 'engaged' call diverts on an iPhone?

[TREMAiNE]

I know how to set up call diverts on an iPhone, so that any incoming calls to Number A divert to Number B.

However, I need to set it up so that calls to Number A go through to Number A, but if Number A is already in a call, it then diverts to Number B.

Any ideas how to do this?

[QuartzDad]

GSM codes ftw.

Dial *67*numberB#

https://www.techbout.com/conditional-call-forwardi... for further details.

[anonymous-user]

I’d google ‘divert on busy (your carrier)’
Eg ‘divert on busy Vodafone’ is **67* as above post:-

“ Divert calls when your phone is busy

Set up
Call **67* followed by the number you want to divert your calls to (replacing the first 0 with +44) then press #
You'll get a pop-up message saying call forwarding is on.
Turn off

Call ##67#
You'll get a pop-up message saying call forwarding is off.”