Sales and Use Tax Practice Ryan has the largest transaction tax practice in North America. We are known for our ability to find tax refund and reduction opportunities and aggressively fight for these dollars. Our Firm reviews all elements of our clients' sales and use tax transactions and ensures that no issue is left on the table. Our typical clients are Fortune 1000 companies that have numerous transactions, complicated accounting systems, and complex issues. Services Provided: We offer our clients a full range of sales and use tax consulting services, including: