The main objective of this study is to assess whether tax compliance during inspection procedures is higher on the island of Príncipe than on the island of São Tomé. Thus, based on the tax corrections to the tax base of the two islands and using a model estimated using the Ordinary Least Squares method, it can be seen that on the island of Príncipe there is a preponderance of voluntary regularisations made to the tax base compared to all the tax corrections made during the inspection procedure, compared to the situation on the island of São Tomé, where voluntary regularisations have a lower preponderance in all the tax corrections made. The results allow us to conclude that tax compliance during the inspection procedure is higher on the island of Príncipe than on the island of São Tomé.