Two competing conceptualizations of corruption in the literature view it either as efficient or burdensome from firms' perspective. Using data on the prevalence and the nature of firms' interactions with tax authorities in twenty-eight Eastern European and Central Asian (ECA) countries, this paper contributes to evaluation of competing ideas in the literature about firms' experience of corruption in tax administration. Special emphasis is given to examination of taxation-related determinants of corruption prevalence (frequency and magnitude of bribery), as well as the effect of the interaction with tax authorities on perception of tax and overall corruption. Regardless of country context, it appears that perceived corruption in tax administration and actual experiences with bribery during interactions with tax officials more than anything else affect the overall perceptions of corruption, thereby supporting the conceptualization of corruption in tax administration as burdensome, rather than efficient.