Introduction Researchers and practitioners interested in the tax burdens of companies almost exclusively focus on direct tax costs (eg, Slemrod, 2004; Vandenbussche et al, 2005). However, in addition to tax payments, companies are confronted with costs to comply with the tax legislation, and these costs can be significant. Small and medium-sized enterprises (SMEs) are especially burdened by compliance costs as they often do not have in-house specialists to deal with the many bureaucratic and legal knowledge requirements (Gurd et al, 1998). In fact, tax compliance costs (TCCs) rank among the top burdens as perceived by SMEs (O'Reilly, 2005). For instance, for the UK Chittenden et al (1999) show that 25% of the total tax burden for small limited companies is related to self-reported costs of compliance. Despite heightened public and political sensitivity for TCCs, there are only a handful of empirical studies investigating this topic. With the intention of broadening the empirical evidence, we examine the TCCs of Belgian SMEs located in Flanders. To our knowledge we are the first to do so. As well as being characterized for its high tax rates on companies ö the Belgian total tax burden is as high as 58%öBelgium is a particularly interesting country to assess TCCs in the sense that it has a very complex tax system. There are no fewer than ninety-two different taxes imposed by the Belgian authorities (overview in appendix). This is a very high number compared with other countries. In the UK, for example, only twenty-two charges exist and in Australia fifty-six taxes are levied (PwC and Federation of Enterprises in Belgium, 2009). Moreover, new taxes are frequently introduced in Belgium and existing charges are often adjusted. This results in new compliance costs because of initial learning costs (Holtzman, 2007). Of the ninetytwo taxes imposed by the Belgian tax system, thirty-nine are taxes collected. Taxes collected are taxes such as employee social security contributions that are gathered and subsequently transferred to the government by a company. Contrary to taxes borne (eg corporate taxes), these taxes will not directly affect a firm's results. However, the taxes collected often generate the highest part of a company's compliance costs and thereby indirectly influence a company's bottom line. Firms act as subcontractors of