|The term NFFE or non-financial foreign entity means a foreign entity that is not a financial institution (including a territory NFFE). The term also means a foreign entity treated as an NFFE pursuant to a Model 1 IGA or Model 2 IGA.|
UK HMRC FATCA Guidance (September 14, 2015) paragraph 02.06:
An NFFE is any non-US entity that is not treated as a Financial Institution. An NFFE will either be an Active NFFE or a Passive NFFE.