Nigeria's Federal High Court recently issued a decision regarding the retroactive application of changes in tax law. The case concerned a loss-making Nigerian company with foreign ownership and changes in the minimum tax made by the Finance Act 2019, which was signed into law on 13 January 2020. This included the repeal of the minimum tax exemption for foreign-invested companies with at least 25% imported equity capital (foreign ownership). Before filing its return for the 2019 tax year, which was due in June 2020, the Nigerian company sought confirmation from the Federal Inland Revenue Service (FIRS) on whether or not...