Openline pairs cleanly with a Deutsche Telekom (Germany) primary line. Your Deutsche Telekom (Germany) SIM (physical or eSIM) keeps handling your personal calls, SMS, and 2FA; Openline handles cellular data at travel prices.

How to set it up

  1. Install Openline as a second eSIM. Do not remove your Deutsche Telekom (Germany) line.
  2. Once both lines are visible, set Cellular Data to Openline for the country you're travelling in.
  3. Keep Default Voice Line on your Deutsche Telekom (Germany) line so calls to your regular number still reach you.
  4. Turn Data Roaming off on the Deutsche Telekom (Germany) line so it never accidentally picks up expensive roaming.
  5. Turn Data Roaming on on the Openline line — that's required for travel eSIMs by design (Openline isn't charged as roaming to you).

Notes for Deutsche Telekom (Germany) customers

  • Wi-Fi calling on your Deutsche Telekom (Germany) line keeps working while Openline runs — a helpful failsafe when a hotel Wi-Fi is decent but a partner cell isn't.
  • If you have Deutsche Telekom (Germany)'s built-in international roaming plan, disable it before your trip or you'll double-pay: Openline will handle data, and your Deutsche Telekom (Germany) plan will still bill you for it if left on.
  • Deutsche Telekom (Germany) may occasionally push a "Welcome abroad" SMS. Ignore it — it's informational, not a bill unless you actually use their roaming.

Still stuck?

Reach Openline support 24/7 through any of these channels:

When you write in, include your purchase code (the OL-… code we emailed you) and, if the eSIM is already installed, its ICCID (Settings → Cellular → tap the Openline line). That's enough for us to find your plan and diagnose without back-and-forth.