When it comes to the U.S. and for example Switzerland, there are two FATCA model types.
Model 1, chosen by most European countries, is based on the principle of automatic exchange of information. Financial institutions provide details of all capital subject to US tax to their local authorities, who pass these details on to the IRS.
Switzerland opted for Model 2, according to which Washington is supplied with information directly by the financial institutions – but this only concerns capital held by American customers who consent to their details being released.
For customers who do not consent to this, the financial institutions must tell the IRS the number and the total value of these accounts. The IRS can then put in a request for “administrative assistance” to the Swiss government to get the full details.
The IRS is withdrawing their voluntary compliance initiative this year and anyone who has not filed and reported their foreign financial assets is in for a big surprise. But this is not only Americans and the IRS. Many countries now have their own version of FATCA and in exchange for cooperating with the IRS regarding their American owned bank accounts the IRS is reporting to them information concerning their national individuals and entities that own financial assets here in the U.S.A.