FATCA (FORM 8938)
***FBAR relates to foreign accounts, 8938 relates to foreign assets.
Form 8938 relates to "specified foreign financial assets". An obligation to file Form 8938 will depend on 4 factors, relating to the aggregate value of all the foreign assets of the taxpayer(s):
1) The filing status of the taxpayer(s). (Married filing jointly, married filing separately, etc.)
2) The aggregate value of foreign assets on the last day of the tax year.
3) The highest aggregate value of assets during the tax year.
4) The tax residence of the taxpayer (in the US, or abroad).
A US taxpayer, resident in the US, filing a US return as 'married-separately', with the highest aggregate foreign asset value for the tax year occurring on the last day of the tax year, will have a filing threshold of $50,000.
US taxpayers, resident in the US, filing a US return as 'married-joint', with the highest aggregate foreign asset value for the tax year occurring on the last day of the tax year, will have a filing threshold of $100,000.
A US taxpayer, resident in the UK, filing a US return as 'married-separately', with the highest aggregate foreign asset value for the tax year occurring on the last day of the tax year, will have a filing threshold of $200,000.
US taxpayers, resident in the UK, filing a US return as 'married-joint', with the highest aggregate foreign asset value for the tax year occurring on the last day of the tax year, will have a filing threshold of $400,000.
Filing thresholds can trigger from $50,000 to $600,000. (The latter being the highest value attained during the year for taxpayers filing married-joint, resident in the UK, but who have below the $400,000 threshold of aggregate assets for the last day of the year. See details.)
http://www.irs.gov/pub/irs-pdf/i8938.pdfRegarding joint accounts owned with an NRA (non-US filing), if filing married-separately from the UK, the joint US filing owner includes the
entire value of the jointly owned asset to determine the total value of all of that joint owner's specified foreign financial assets.
All the above is in my opinion only. I may be wrong