Multinational companies are taxed in each country in which they operate. As well as income taxes, they will also pay sales taxes, payroll taxes and any other taxes which are levied in the countries in which they run their business. The advantage multinational companies have is that they can move revenues and costs between different countries, depending on which countries charge lower taxes. Although there are usually anti-evasion laws in place to minimise the extent to which they can do this. Hopefully that explains a little about why and how multinational companies pay tax.