This study aimed to build a model and set of criteria to evaluate and select business accounting software providers for Truong Son Technology Investment and Development Joint Stock Company. The study helped choose the most suitable supplier that meets the criteria that the company desired. The research proposed the Technique of Order Preference Similarity to the Ideal Solution (TOPSIS) model and was also applied in the case of selecting accounting software suppliers for Truong Son Technology Investment and Development Joint Stock Company. There were 5 business accounting software packages considered: Misa business accounting software, Bravo accounting software, FAST Accounting software, Effect accounting software, and Gamma accounting software. The ranking results of accounting software providers at Truong Son Technology Investment and Development Joint Stock Company were as follows: A1 (Misa Business Accounting Software) was the best supplier, second-ranking was A3 (FAST Accounting software), followed by A2 (Bravo Accounting Software) in third place. The findings of this study could be used as a valuable reference for businesses to choose the best supplier.