Hello, double taxation agreements between two countries define how much % of tax earned in country A will be deducted from the taxes of country B and vice versa. The goal is NOT to pay double tax.
Here is an example: 10% BVI-Tax and 20% Swiss-Tax could become to 15% Swiss-Tax when the taxes of BVI can be used by 50% to reduce Swiss taxes.
How much % this is in particular, changes on a regular basis (yearly in the most cases). It will be calculated by export surpluses between these two countries and some other factors. So you need to contact a tax consultant︀ in Switzerland or BVI.
