Experian, one of the three major credit bureaus in the United States, does not typically have data on consumers' telecommunications accounts, such as their T-Mobile accounts. However, there are a few reasons why Experian might have this information:

1.Data partnerships: Experian may have partnered with T-Mobile or other third parties to obtain customer data. This data could include information such as payment history, account balances, and credit scores.

2.Credit applications: If you have applied for credit with T-Mobile or through a lender that uses Experian's services, T-Mobile may have provided your account information to Experian as part of the credit application process.

3.Credit inquiries: If you have authorized a third party, such as a potential employer or landlord, to check your credit, they may have contacted Experian for your credit report. Experian may include information from your T-Mobile account in your credit report if it has been provided by T-Mobile or other sources.

4.Public records: Experian may also obtain information from public records, such as bankruptcy filings or court judgments related to your T-Mobile account.

It's important to note that Experian and other credit bureaus are regulated by federal and state laws, which require them to follow specific data collection and privacy practices. They are not allowed to collect or use information for purposes other than those permitted by law. If you have concerns about the information Experian has on file, you can contact them directly to request a copy of your credit report and dispute any inaccuracies you may find.