The guidance note on the payment of top‑up tax under the Global Base Erosion and Profit Shifting (GloBE) Minimum Tax outlines the procedural steps for calculating and remitting the additional tax imposed by Barbados' implementation of the OECD Pillar Two framework. It explains that the top‑up tax is due when the effective tax rate on multinational income falls below the 15% global minimum, and details the methodology for determining the taxable base, allowable deductions, and credit mechanisms. The note specifies that payments must be made electronically through the Authority's online portal within 30 days of filing the annual return, and it provides the applicable interest rates for late payments. Additionally, it clarifies the interaction of the top‑up tax with existing withholding taxes and the process for claiming refunds if over‑payments occur. The Authority also outlines audit rights, documentation retention obligations, and the availability of voluntary disclosure programmes for correcting earlier under‑payments. Finally, the note includes sample calculations to illustrate the tax impact on typical corporate structures and offers practical advice on aligning internal tax governance with the new filing requirements.