A credit report is a detailed report of an individual's credit history prepared by a credit bureau. Credit bureaus collect information and create credit reports based on that information, and lenders use the reports along with other details to determine loan applicants' credit worthiness. In the United States, there are three major credit reporting bureaus: Equifax, Experian and TransUnion. Each of these reporting companies collects information about consumers' personal details and their bill-paying habits to create a unique credit report; although most of the information is similar, there are often small differences between the three reports.
Every person with a Swedish national identification number must register a valid address, even if living abroad, since sent letters are considered to have been delivered to that person once they reach the registered address. As an example, Swedish astronaut Christer Fuglesang got a Betalningsanmärkning since a car he had ordered, and therefore owned, passed a toll station for the Stockholm congestion tax. At the time, he was living in the USA training for his first Space Shuttle mission and had an old invalid address registered for the car. Letters with payment requests did not reach him on time. The case was appealed and retracted, but the non-payment record remained for three years since it could not be retracted according to the law.
This is as bad as it gets, as this will have many negative effects on your life. Lenders, with the exception of those who specialize in lending to borrowers with bad credit, will not approve you for any loan product, even if you can provide a sizable down payment or collateral, and insurance agencies will likely refuse you based on the risks you pose. Often, employers that check your credit will not hire you, whether there is another viable candidate or not.