BDO knows accounting. BDO USA is the US member of BDO International, one of the largest accounting firms outside of the Big Four (Deloitte Touche Tohmatsu, Ernst & Young, KPMG, and PricewaterhouseCoopers). BDO USA offers midsized companies a broad range of accounting and consulting services such as auditing, tax planning, litigation consulting, and appraisals and valuations. The company has almost 2,200 staff members and about 270 partners. It has more than 40 offices in the US. More than 400 additional offices are operated by independent US firms that are members of the BDO Seidman Alliance.