A growing number of U.S. taxpayers are getting familiar with another IRS acronym: FBAR. The term refers to Report of Foreign Bank and Financial Accounts, AKA Form TD F 90.22.1. If you’re a U.S. citizen, resident, or domestic partnership, corporation, trust or estate with a financial interest in or authority over a financial account(s) in any foreign country whose aggregate value tops $10,000, you’re expected to file an FBAR.

What’s more, the deadline is coming up: June 30. Note: This is the date the form must be received by the Department of the Treasury; it’s not enough just to have mailed the report by the 30th. And the deadline holds even if you’ve requested an extension in filing your federal income tax return, the IRS states in this set of FAQs. (The FBAR is not filed with the federal tax return.)

The FBAR “has become an area of increased IRS scrutiny in recent years,” according to this analysis from KPMG. The reason? The IRS wants to boost income tax compliance by U.S. taxpayers holding assets outside the U.S.

The IRS appears to be meeting its goal, judging by a 2010 report from the Treasury Inspector General for Tax Administration (TIGTA). The number of FBAR-related exams nearly doubled between fiscal years 2004 and 2009, rising from 334 to 656, TIGTA found. Not surprisingly, FBAR penalty assessments nearly quadrupled during this time, jumping from $4.2 million to $20.5 million.

Just what is a “financial account” that requires reporting on an FBAR? The term covers  bank, securities, securities derivatives or other financial instruments accounts, as well as savings, demand, checking, deposit or other accounts maintained with a financial institution, the IRS says. It also generally includes any accounts in which the assets are held in a commingled fund, and the account owner holds an equity interest in the fund, including mutual funds.

The requirement to file an FBAR extends to company owners in some cases. The IRS provides an example: A U.S. corporation owns a foreign company that has foreign accounts. Even if the corporation files an FBAR for the accounts, an owner of the company who holds more than 50 percent of the value of the shares will have to file as well. Similarly, a partnership in which a U.S. person owns, either directly or indirectly, more than 50 percent of the profits, interest or capital also would file, KPMG notes.

In addition, an FBAR must be filed even if an account was open only for part of the year, CPA Gary L. Howard writes in this post in AICPA Insights.

The FBAR form itself requires, among other pieces of information, the type of filer (i.e., individual, partnership or corporation), and for each account: the type of account and its maximum value during the year, the name of the financial institution at which it’s held, and the account number. 

If you don’t get around to filing an FBAR, you may find yourself facing civil and/or criminal penalties. The penalty for a pattern of negligent violations can go up to $50,000. Taxpayers that willfully violate the FBAR requirements (after October 22, 2004) may face penalties of up to $100,000, or 50 percent of the amount in the account at the time of the violation, the IRS says.