It's rare that a free credit score truly has no strings attached. In the best-case scenario, you get added to the company's mailing list and have to manually unsubscribe if you don't want to be. Worst-case scenario, you enter your credit card and get automatically enrolled in credit monitoring services. This will show up as a recurring monthly charge on your credit card until you cancel it. However, there's usually a small window -- seven or 14 days -- after you get your free credit score in which you can cancel your subscription without being charged for credit monitoring.
A credit report includes information on where you live, how you pay your bills, and whether you’ve been sued or have filed for bankruptcy. Nationwide credit reporting companies sell the information in your report to creditors, insurers, employers, and other businesses that use it to evaluate your applications for credit, insurance, employment, or renting a home.