BEFORE you file your tax return, ALWAYS mention THIS to your accountant.

There are three basic tax reasons you may be fined and imprisoned. The first is for failure to file. The second is for failure to pay. And the third, and often the most common, yet the most overlooked is the failure to file a complete and accurate return. If the return is incomplete, or inaccurate, you are the only one responsible. You may turn to your accountant, but the tax account is yours and the IRS will hold it against you. The following is a list of things you MUST mention to your accountant because you may have to prepare a specified form or disclosure. 

If you are a US Person or Entity, that is, a citizen, resident, or otherwise US taxpayer due to physical presence (and not excluded by treaty or special rules) then make sure you mention this:

1. Transfers of property to a foreign corporation.

2. Ownership Interest in a Foreign Trust.

3. Receipt of foreign gifts.

4. Foreign Bank Accounts under your name.

5. Foreign Bank Accounts under entities or people you control.

6. An interest in any type of account held at a foreign financial institution.

7. Ownership Interest in a Foreign Corporation.

8. Ownership Interest in a Foreign Partnership.

9. Ownership Interest in a Foreign Disregarded Entity.

10. Operations in a Country with a Tax Treaty with the US.

11. Renunciation of US citizenship.

12. Renunciation of long-term residency from the US.

13. Foreign Pension Plans.

14. Foreign Passive Income: Rent, Dividends, Interest.

15. Whether you gave gifts exceeding $10,000 or its equivalent in Fair Market Value.

16. Whether an adult family member died.

17. Whether you have an ownership interest in a domestic trust.

18. Whether your domestic LLC (or any other entity taxed as partnership) had a foreign partner.

If you are a foreign person or entity with a financial interest in the United States, then make sure you tell this to your accountant. 

1. Whether you disposed of real estate during the year. 

2. Whether you have a closer connection to a country other than to the United States

3. Whether a family member with a US interest died during the year 

4. Whether you are a citizen or national of a country with which the US has a treaty

5. If you are a foreign corporation, whether you have an ownership interest in a US entity.

This is by no means an exclusive list of things you need to mention. Rather it should be used as a complement to what you typically provide your accountant before your return is prepared. If you have determined that you already filed and you missed something, you should contact a tax attorney and not an accountant. This is because the attorney, as opposed to the tax preparer, holds attorney client privilege, whereas everything you tell your accountant, if it turns out to be a criminal indictment, must be disclose to the government.