Business abbreviations are commonly used in the business world to shorten lengthy titles and phrases. The most common abbreviations are CORP (4 letters), INC (3 letters), LTD (3 letters), ULT (3 letters), ASSN (4 letters), BROS (4 letters), INST (4 letters), and INCORP (6 letters). CORP stands for corporation, INC stands for incorporated, LTD stands for limited, ULT stands for ultimate, ASSN stands for association, BROS stands for brothers, INST stands for institute, and INCORP stands for incorporated.