C / O is an abbreviation for "care of", used in addresses and correspondence when the recipient is staying at someone else's home or receiving mail through a third party. Learn the origin, context, and other meanings of C / O , as well as related terms and examples. Understanding what does C/O mean in mailing is essential for sending mail accurately. Whether for business correspondence, temporary stays, or third-party handling, using C/O correctly ensures mail reaches the intended recipient. C / O is an abbreviation for care of, used in addresses when the person you are writing to is staying at someone else's home. Learn more about its pronunciation, usage and translations in different languages. The Difference Between Inc. & Ltd. & Co.. If you're starting a small business you must decide its legal structure. Legal structure is usually determined by the business type, the number of owners ...