ABSTRACTBased on comprehensive research among boat operators and navy personnel working on the Congo River (DRC), this article explores how assessments of ‘taxation’ are shaped by the interplay of legitimation and ‘officialisation’. As such, it draws upon and contributes to scholarly debates on taxpayers’ attitudes towards taxation. While boat operators resent having to pay a plethora of authorities, including the navy, along the Congo River, the article demonstrates how they locate these ‘taxes’ on a spectrum from more to less legitimate. These assessments are shaped by various factors: authorities’ legitimacy as ‘measured’ by their official mandate and importance; public and non-official service provision; and the deployment of symbols of ‘stateness’. In interaction, these factors legitimise and ‘officialise’ ‘taxes’ by the navy that are prohibited in legislation. These findings caution against the a priori use of the labels ‘official’ and ‘non-official’, emphasising the need to better grasp these notions’ emic understandings.