O2 runs Germany’s third mobile network under the Telefonica brand. It’s also the host network for several budget carriers, including 1&1 and various Drillisch brands (smartmobil, winSIM, PremiumSIM). If you’re on any O2-network carrier, the GSM codes below will work for you.
GSM Forwarding Codes for O2
O2 uses the standard GSM forwarding codes. Open your dialer and enter the code, replacing [number] with the full destination number (including country code).
| Forwarding Type | Activate | Deactivate | Check |
|---|---|---|---|
| All calls | **21*[number]# | ##21# | *#21# |
| No answer | **61*[number]**[seconds]# | ##61# | *#61# |
| Busy | **67*[number]# | ##67# | *#67# |
| Unreachable | **62*[number]# | ##62# | *#62# |
| Cancel all | ##002# |
Replace [seconds] with 5, 10, 15, 20, 25, or 30. For business use, 15 or 20 seconds strikes the right balance between giving you time to answer and not making the caller wait too long.
Example: Forward unanswered calls after 15 seconds:
**61*+491701234567**15#Generate your code automatically with our interactive forwarding tool.
Setup via the Mein O2 App
The Mein O2 app (iOS and Android) provides a visual way to manage forwarding.
- Open Mein O2 and log in
- Go to My tariff or Tariff & SIM
- Find Call settings or Rufumleitung
- Select the forwarding type you need
- Enter the destination number and save
The app shows your currently active forwarding rules, making it easy to verify what’s configured.
Setup via the Online Portal
O2’s web portal at o2online.de offers the same forwarding options:
- Log in to your Mein O2 account
- Navigate to your contract or SIM settings
- Find the forwarding section under call settings
- Configure your rules and save
O2 Customer Service
Dial 55222 from your O2 phone (free) or 089 787 979 400 from any phone. A support agent can activate or troubleshoot forwarding.
Things to Watch Out For
- Roaming limitations: This is O2’s biggest quirk for forwarding. Some O2 tariffs restrict or disable call forwarding while roaming outside Germany. If you travel frequently and rely on forwarding, check your tariff details or call 55222 to confirm.
- Forwarding costs: On O2 Free and O2 Mobile contract plans, forwarded calls count against your included minutes. Prepaid customers pay per-minute rates for the forwarded call leg.
- MVNOs on the O2 network: If you’re with 1&1, smartmobil, winSIM, or another Drillisch brand, GSM codes work the same way. However, app and portal management differs. See the 1&1 and Congstar guide if you’re on 1&1 specifically.
- VoLTE forwarding: If you have VoLTE (Voice over LTE) enabled, forwarding works the same way. No extra steps needed.
Frequently Asked Questions
Does call forwarding work on O2 prepaid?
Yes. O2 prepaid SIMs support call forwarding via GSM codes. Each forwarded call is charged at your prepaid tariff’s per-minute rate. Make sure you have enough credit on your account.
Why does forwarding stop working when I travel abroad?
Some O2 tariffs disable forwarding during roaming. This is a tariff restriction, not a technical limitation. Contact O2 support at 55222 to check whether your plan supports forwarding while abroad, or consider upgrading to a plan that includes it.
Can I set different forwarding destinations for different situations?
Yes. You can configure each forwarding type independently. For example, forward unanswered calls to one number (code 61), busy calls to another (code 67), and unreachable to a third (code 62). Each rule works separately.
Can I forward my O2 calls to Safina?
Yes, Safina works with O2 and every carrier on the O2 network. Use conditional forwarding (no answer, busy, unreachable) with your Safina number. Your phone rings normally, and Safina steps in only when you can’t answer. Learn more about Safina.