Hi raskabass,

The culprit might be a messaging application that uses MMS as a fallback if the recipient does not have the same messaging app. For example, I have Signal on my mobile phone and have configured it so that it is my default SMS/MMS app, too. In this case, the app sends Signal messages to other Signal users and SMS/MMS to people who do not have Signal installed.

Also, you could have fallen victim to some malware app that sends expensive text oder multimedia messages to foreign networks, see for example Is My Phone Compromised by MMS Malware? : Cybersecurity101 (reddit.com)

Fingers crossed that it is not the malware.

Best wishes,

Thomas

@teezeh 

I'll check our default applications, but wouldn't the charges be under "Verbindungspreise SMS/MMS ServiceCenter" if this was the case?  The charge I received is under "Verbindungspreise Telefonie".

Hi,

Since you wrote

I do see the Einzelverbindungsnachweis lists MMS charges over the month

 I thought this was about MMS. Did I miss anything?

Best wishes,

Thomas

@Sarah D. 

I am available after 1700. I can be available earlier if a time is coordinated.