A Data Universal Numbering System (DUNS) number is a unique nine-digit identifier for businesses. It's issued by the credit bureau Dun & Bradstreet to any business that completes their informational profile. DUNS numbers are standardized across global industry and trade associations and are registered by more than 300 million businesses.
DUNS numbers are similar to a social security number for a business. They're used for business credit reporting, and can help lenders and potential business partners determine the reliability and financial stability of a company. They can also help a company establish a business credit score and negotiate better payment terms with suppliers. DUNS numbers are free for U.S. companies.