The TADAT website, jointly run by the IMF and World Bank, offers various details on what IFIs consider to be the key performance indicators on which to assess the quality of tax administration, as well as different country reports.
The ATAF website provides access to a variety of resources compiled by the umbrella-body of African revenue authorities, from research papers to revenue data.
The ICTD-UNU WIDER Government Revenue Dataset is the best source of both tax and non-tax revenue for cross-country comparative analysis. The website includes a guide on how to use the dataset and links to research papers based on the data.
The go-to website to explore the World Bank approach to supporting domestic revenue mobilisation around the globe, it also contains specific pages directly linking to all of their work on health taxes, gender and tax and environmental taxation.
The official website of the ATI, a multi-stakeholder partnership which aims to support fair domestic revenue mobilisation to achieve the SDGs across low-income countries, which includes many reports on tax expenditure and tax incentives amongst others.
A joint initiative from the Institute of Fiscal Studies and the Overseas Development Institute, the TAXDEV website links many different papers on tax policy making in low- and middle-income countries, with a particular focus on Ethiopia, Ghana, Uganda and Rwanda.
A joint initiative by IDOS and CEP, the website provides access to the most comprehensive country-level dataset on tax expenditures, as well as to the methodology used in its production and to papers making use of it.