This study sought to measure the compliance costs of the principal business taxes imposed by central government. The main method was two large-scale random mail surveys, one related to the costs employers face in dealing with PAYE (including other witholding taxes) and FBT, and the other with GST and income tax on sole proprietors, partnerships, companies and trusts. Two main conclusions emerge about the compliance costs of business taxes: (1) they are very large and cumulative in their impact; (2) they are very regressive, individually and collectively, falling with disproportionate severity on smaller businesses.