FATCA implementation in Switzerland is based on FATCA Model 2 Agreement, which means Reporting Swiss FIs will disclose account information directly to the US tax authority IRS with the
consent of the concerned US account holders or non-participating FI’s.
The United States can request account information on non-consenting US account holders or non-participating FIs only through normal administrative assistance channels.
This requires you as a Reporting Swiss Financial Institution (FI) to transmit account data to the Swiss Federal Tax Administration (FTA).
The FTA as the competent Swiss authority receives such a group request and will request the information holding FI to identify the account holders or the nonparticipating FIs concerned and provide the FAT in addition to the reportable data in electronic form (FATCA-XML) separate documents enabling the FTA to verify whether it is in fact a reportable account. The data and documentation you may need to send to the FTA additionally includes a SEI XML file and further documentation in pdf format within the same deadline of 10 days
Technical Specification and User Guide for Financial Institutions according to FATCA IGA 2
FATCA Information Delivery (PDF, 330 kB, 02.10.2015)
SEI-XML (ZIP, 7 kB, 02.10.2015)