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Kromster's profile

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1 Message

Thursday, March 23rd, 2023 2:24 AM

Problem with changing phone number


​​Today I became your client and when I came home I decided to change my phone number by following this instruction:​​
​​But I can't change the number due to an error: "Please provide valid input data. (MNC12)"​​

​ ​ ​ ​ ​​

Community Support


229.6K Messages

11 months ago

Hello there @Kromster, that's not the experience we want you to have with attempting to changing your phone number.


Let's meet in a Direct Message, by locating the chat icon next to the bell icon in the upper right-hand corner of the forums page.


What to know before you change your number

  • Within 30 days of activation, it’s free. You can head to your local AT&T store.
  • Activated your service more than 30 days ago? There’s a $36 change fee. 

We look forward to chatting with you soon.


Ashley, AT&T Community Specialist 

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