Hello @mieszkom,
We appreciate you reaching out to us on the Community Forums! I’m sorry to hear you are unable to access your online account. I know how important it is to be able to view your bill and usage. I can help you with this!
Thank you for trying a different browser, this helps narrow the issue down. We also have a quick troubleshooting guide for myAT&T issues. This may provide some assistance.
This could also be an account specific issue. I will be reaching out to you in a private message, in order to gather more information. Please check your Forum’s Inbox for this!
I look forward to working with you. Have a great weekend!
Jonathan, AT&T Community Specialist