8 requests information about foreign financial assets (like stocks, bonds, life insurance policies, etc.) and accounts, while the FBAR requests information only about foreign financial accounts. The information reporting is largely duplicative.
Yes, most people have to file both. Married individuals filing jointly and residing in the United States are required to file Form 893
8 if their foreign financial assets are valued greater than $100,000 on the last day of the year or greater than $150,000 at any point during the year.
Yes, if you are required to report foreign financial assets. It is not optional. For example, unmarried individuals residing in the United States are required to file Form 893
8 if the market value of their foreign financial assets is greater than $50,000 on last day of the year or greater than $75,000 at any time during the year (filing jointly the limit is $100,000).