How do Credit Bureaus Get Your Information?

Three major credit bureaus

The top three credit bureaus (also known as credit reporting agencies) are Experian, Equifax and TransUnion. When you’re applying for credit, lenders depend on the data provided by these bureaus to make their decision whether or not to lend you money. So where does this data come from in the first place?

https://blog.myfico.com/how-credit-bureaus-get-your-info/