This paper conducts an impact evaluation of the effects of two tax administration
interventions—a taxpayer register expansion and education programme, and a new electronic filing
system for presumptive tax—on the number of small business taxpayers and presumptive tax
revenues in Uganda. Using a difference-in-differences approach and administrative data covering
both presumptive taxpayers and comparable small corporate income taxpayers, we find that the
number of small business taxpayers filing tax returns and presumptive tax revenues increased
substantially after the interventions. We argue that the interventions complement each other
because both interventions were established around the same years, and the taxpayer register
expansion programme focused on not only registering but also educating taxpayers with regard to
tax compliance. We analyse the cost-effectiveness of the taxpayer register expansion programme
and find that the benefits outweigh the costs.