The H&R Block acquisition of American Express Tax & Business Services creates a new leader among middle-market accounting firms, leapfrogging Grant Thornton to the top of the “Second Six.”

Last week, H&R Block announced plans to merge the American Express tax division with its existing RSM McGladrey Business Services subsidiary, which provides non-attest accounting and business consulting services. Combined with independently owned McGladrey & Pullen, which provides attest accounting services to RSM McGladrey clients, the resulting accounting group will account for more than $1 billion in revenue, according to H&R Block.