You may want to consult an expert on IRS policy issues, as well as the IRS "Workbook" on FBAR enforcement: http://www.irs.gov/businesses/small/...159757,00.html and the IRS FAQ: http://www.irs.gov/businesses/small/...210244,00.html

As a practical matter, enforcement is stricter as against those taxpayers with a presence, assets or income in the USA. It also matters whether there is unpaid tax. If the violation is substantial you may want to have a tax attorney negotiate on your behalf since s/he can do so keeping you anonymous until such time as an accord in principle is reached. And professional privilege keeps your information secret until then.

As regards freizugigkeits kontos the issue seems to be whether unapproved pension schemes are outside the scope of FBAR reporting. Certainly many, probably most, US persons residing abroad do not report such things as pensions, children's trust funds and mortgage escrows. The advice given by white-shoe law firms in the USA is to report every such account, even accounts collateral to investment schemes (such as Lloyd's of London insurance syndicates) and even when the applicability of the FBAR scheme is doubtful. The penalties are simply too draconian to ignore the issue.

Form 3520 may also need to be filed, depending on the nature of the account.

There is a prior discussion of freizugigkeits kontos here: Freizuegigkeitskonto [vested benefit account] One issue to keep in mind is potential double taxation because of the temporal and definitional conflicts.