Why do my scores vary between the 3 credit bureaus?

The three major credit bureaus, Experian, Equifax and TransUnion are for profit businesses, not government agencies. Their main business is collecting data about YOU from creditors and then reselling that data to lenders, employers, insurance companies, utility companies, and most recently to YOU, the consumer. Since these three companies are competitors, and DO NOT share data with one another, it is very common that the data they house in your file will differ because not all creditors report to all three bureaus. That explains the variance in the scores as each line item affects the score either up or down.