TransUnion is a nationally recognized credit bureau that provides detailed credit reports, credit scores, and identity protection tools. It is trusted by lenders when approving credit card applications, personal loans, and even apartment rentals. When you apply for a cashback card, balance transfer card, or 0% APR offer, there's a good chance TransUnion data is being reviewed. It receives real-time updates from banks and creditors and helps build a financial profile that lenders use to gauge creditworthiness. In contrast, Credit Karma only displays this information—it does not generate or verify it. That distinction is key when applying for financial products.