FATCA is a US tax reporting regime that has been adopted by a number of countries outside the US.
Although the details vary slightly between countries, in most cases banks and financial institutions in the foreign country where FATCA has been adopted are required to report accounts held by US citizens and green card holders.
In most cases the institutions report these accounts to the revenue authority of the foreign country, and the revenue authority the reports the accounts to the IRS.
It is imperative that US citizens and green card holders disclose their foreign accounts to the IRS before the foreign accounts are reported to the IRS. This includes citizens and green card holders who may be living abroad. See US Citizen or Green card Holder Living Abroad?
US citizens and green card holders should generally disclose their unreported foreign accounts through Voluntary Disclosure. Some forms of Disclosure provide strong protection against criminal proceedings, but can be costly as far as penalties are concerned; while others do not provide protection against criminal proceedings, but allow for low or minimal civil penalties. See Foreign Accounts?
We have the experience to identify the best procedure and to assist clients through the Disclosure process.