Setting up call forwarding with 1&1

First: when should calls be forwarded?

There are three kinds of forwarding to choose from: immediately (your own phone stops ringing altogether), when busy (the second caller does not land on a busy tone) and on no answer (delayed — you get to pick up first). The standard case for businesses: combine delayed, when busy and when unreachable. Everything stays as it was; only voicemail is replaced. The basics of all four connection routes are explained in "Setting up call forwarding: the four routes and their pitfalls".

Mobile: forwarding by key code

The codes are a network standard (GSM) and work on any handset:

1. Have the target number ready — the number calls are forwarded to.
2. Type the code into the phone app, like an ordinary phone number.
3. Press the call button — the network confirms with an on-screen message.

The waiting time before the no-answer rule fires can be set between 5 and 30 seconds in steps of 5; 20–25 seconds has proven itself. 1&1 describes no route through the 1&1 Control-Center for the mobile number — its help centre gives only the GSM codes for this (as of 2026-11-02). As an alternative to the code you will find call forwarding in the telephony settings on iPhone and Android.

DSL landline: Control-Center or router

On a 1&1 landline connection telephony runs over DSL — and therefore over your router (with 1&1 often a FRITZ!Box). So there are two places to set the forwarding up:

1. In the customer portal (Control-Center): according to the 1&1 help centre you click "Vertrag" (contract), choose your contract for internet and landline and then "Weiterleitung" (forwarding). There you select the number, tick "Anrufe weiterleiten" (forward calls), enter the target number and save. Whether the Control-Center can also forward with a delay or when busy, the help page does not say (as of 2026-11-02) — to replace voicemail, check this in the portal or set the delayed forwarding up in the router. Advantage: immediate forwarding applies even when the router is off or faulty.
2. In the router: a FRITZ!Box can create forwarding rules per number — handy when you want to treat several numbers differently. The step-by-step guide for that is in "Setting up call forwarding on the FRITZ!Box". Drawback: it only applies while the device is running.

For permanent operation — forwarding to an AI phone assistant, for instance — the network-side route through the portal is the more robust choice.

Pitfalls: caller ID, cost, duplicate rules

Caller ID (CLIP): if your provider's network does the forwarding (key code, app, customer portal), the standard has the destination receive the caller's number. Your own number typically arrives only when a FRITZ!Box or phone system forwards the call itself — and then an assistant cannot capture the caller's number automatically. Check it after setting up, with a call from a second phone.

Cost: the forwarded leg of the call is paid by the line owner. 1&1 states that forwarding to another number may incur additional connection charges, on the landline depending on tariff and target number (as of 2026-11-02). 1&1 does not say that a flat rate covers them — check your tariff and price list before forwarding permanently.

Duplicate rules: forwarding in the portal and in the router as well builds effects that are hard to see through. Decide on one place.

What this means for your AI assistant

Nothing beyond the forwarding is needed: with scoco.ai you keep your 1&1 number, nothing changes on your line or your phone system, and basic setup takes about 10 minutes. When a caller number is transmitted, the assistant offers to use it as the callback number — if the caller accepts, it is taken without being read back; with a CLIP problem, that is your own. A dictated number it reads back digit by digit. So after setting up, check with a call from a second phone whether the caller's number arrives in the inbox. A planner in the dashboard shows the right codes, with your scoco number already filled in. Calls are not recorded; transcripts and summaries are produced.