"FATCA generally does not impose compliance obligations on US-based retirement plans.... At this time, Form W8-BEN-E is understood to be a self-certifying form. Plans need not submit along with the form evidence to support eligibility for an exemption. However, it is possible that the final form and/or individual withholding agents may require additional documentation.... If not covered by an exemption, plan representatives should put in place communication strategies to explain to their US taxpayer participants that the plan will require their consent to provide the IRS with identification and account information."