No service/signal outside Germany (International Roaming Blocked)

What plan do you have?
Is this a new contract?
What country are you in?
Have you actually enabled roaming on your device?

Plan: It is an O2 Prepaid SIM card.

New contract: No, I have been using it for a while. Interestingly, the international roaming was working perfectly fine back in April, but it completely stopped working now.

Current location: I am currently in China.

Device settings: Yes, data roaming is fully enabled on my device. I have also tried searching and selecting the network manually, but the phone still shows "No Service" and fails to register on any local network.

It seems like a temporary restriction or network-side block (Auslandssperre) has been placed on my account. Could a moderator please check my status, refresh my network profile, and lift the block for me?

Thank you!

In that case, China is probably the cause, since high costs can be incurred there. Has the credit balance perhaps been used up? 

Hello ​@zww ,
welcome to our o2 Community 😀
Your SIM card is currently blocked with us. Unfortunately, we do not have proof that you are registered at the address on file with us.
In order for us to unblock the card for you, we need appropriate proof.
Please email us, for example, a certificate of residence, hotel bookings, etc., to the following address:
Impressum@cc.o2online.de
Kind regards, 
Solveig 

Hello ​@o2_Solveig,

Thank you for your reply.

I sent the required document to Impressum@cc.o2online.de on June 29th, 2026, at 18:02, The email was sent from my registered email address, containing my full name, phone number, and my customer number in the subject line so your team can easily locate it.

but my SIM card is still blocked at the moment.

Could you please check the current status and let me know the progress of the unblocking process?

Thank you for your support!

Best regards,

zww

You can also try the contact form on the website. 

The mail adress you used is usually not for support requests. 

Emails are processed much more slowly than inquiries submitted through login's communication channels, such as the contact form or chat. In addition, the security department must review them, which can take some time. 

Hello ​@zww,

Unfortunately, we do not have access to the submitted documents. We can only view them once they have been fully processed and your request has been closed. Unfortunately, that is not yet the case.

It is not possible for us moderators here in the community to unblock SIM cards.

I regret that I have to ask you for a little more patience here.

Best regards

Giulia