You would be interested to know that in February last, five European countries – France, Germany, Spain, Italy and the UK – signed a deal with the US. They agreed that they would each enact legislation requiring their local FFIs to collect and report FATCA-style information to their local tax authorities. The European jurisdictions would then transfer the information to the US.
Under such arrangements, the withholding on passthru payments would generally only apply to third-country non-participating FFIs. The obligations under the agreement are reciprocal. However, in order to enter into such a FATCA Partnership, Mauritius would need to amend its laws to address any conflict of laws issues that could arise.