TransUnion (formally known as Callcredit) are one of the three main credit reference agencies in the UK. TransUnion act like a data library, pulling in information from lenders and public bodies.
Credit reference agencies collect information from public bodies and lenders, which is then made available to lenders when reviewing any application for credit. Lenders are required to lend responsibly and using the information in your credit report helps them to make decisions with more confidence.