Yesim Deretam

Yesim Deretam is the Founder and Chief Executive Officer of TAM Accounting Inc., a U.S.-based firm specializing in accounting, finance, and tax advisory services. She has more than 15 years of professional experience in accounting, financial management, and strategic consulting.

Yesim's academic journey spans two continents. She earned her undergraduate degree in Mathematics from Gazi University in Turkey, developing the analytical rigor that would define her career. She went on to complete an MBA at Işık University and later pursued additional university-level education in Taxation and Accounting in the United States, immersing herself in the intricacies of U.S. federal and state tax law from the ground up.

She holds the IRS Enrolled Agent (EA) designation, the highest credential awarded by the Internal Revenue Service, authorizing unlimited representation of taxpayers before the IRS at the federal level. She is also a Certified Tax Coach (CTC), recognized for her expertise in proactive, legal tax minimization strategies.

Over a career spanning more than 20 years, Yesim has built TAM Accounting into a firm serving 5,000+ clients across all 50 U.S. states. Her work sits at the intersection of accounting, international taxation, cross-border financial architecture, and business growth strategy. She specializes in US GAAP Accounting, U.S. company formation, e-commerce accounting for platforms including Amazon and Etsy, IRS audit representation, Effectively Connected Income (ECI) structuring, and the application of U.S.-Turkey tax treaties for cross-border operations.

Yesim is particularly sought after by Turkish entrepreneurs and global businesses entering the U.S. market, helping them navigate not only regulatory complexity, but the strategic decisions that determine whether a company remains a sales channel or becomes a true global brand. Her approach is direct: financial architecture is not built after growth. It is built before it.