On your mobile
Type this code like a phone number and press call:
**21*<number>#
This forwards all calls right away. Check: *#21#, turn off: ##21#. If you'd rather answer yourself first: after 5 seconds **61*<number>**5# (turn off: ##61#). If your phone doesn't accept the code, look in your provider's app for call forwarding (Rufumleitung).
Landline with FRITZ!Box
Open fritz.box, then Telefonie, Rufbehandlung, Rufumleitung, Neue Rufumleitung: all calls, target your assistant number, immediately (no delay), apply.
Other landline (Telekom, Vodafone, o2 …)
In your customer portal under „Anrufweiterschaltung“ set the option sofort (all calls) to your assistant number.
Forwarding applies to every call as soon as it is on. It costs like a call to a German landline – included in most flat rates.
Questions? WhatsApp Vlad in English