Check Settings → Mobile Data → current period roaming. If Roaming is off it should be zero…

Thank you so much for the hints. My problem is that I had never cleared my data usage since I got the phone so now I have 535 GB for current period and 8.1 GB for roaming. From O2 app, I saw 0.4 MB for data used in Ausland. 

Dear @Monamie80 ,

welcome to our community.

You should always turn off the mobile data, when you out of the EU Roaming area.

What does your bill says, does it list connections outside the EU?

Kind regards,

Andrea

Hallo Andrea, does that mean even if data roaming is turned off I would still be charged? Mobile data was turned on but most of the time was on flight mode as I used only WiFi. I haven’t received the bills so far and only 2 SMSes from O2 saying I have reached the €59.50 limit, once for Turkey and the other time for Taiwan. I checked the O2 app for Ausland data usage and it was 0.4 MB. 

Hallo Andrea, I received my latest bill and there are no data roaming charges, phew! Not sure why I received the SMSes though but it was a good reminder to always turn off mobile data in addition to turning off data roaming while traveling outside of EU. Many thanks for your help and I wish you a fantastic weekend ahead!

Hey @Monamie80 ,
so happy to hear and yes rember to tun your data roaming off while travelling outside of EU
A fantastic weekend to you, too

Hey @o2_Matea @o2_Andrea @o2_Jessica, 

I had the same issue today, I received the same message saying that I reached the amount of 59.50 € for data roaming, while I had moblie data and data roaming off before I even left germany, and left them off the whole time, it even says in my o2 app that I have 0MB of data used outside the EU.

Hey @SelimBY,

welcome to the o2 Community :)

Same question to you: Did you recive the bill alredy?

Greetings,
Flo

No I didn’t receive the bill yet, I just got the SMS

Hey @SelimBY,

Then we must first wait for the invoice and see if something was charged and to what extent and why :)

Greetings,
Flo