Generally, items of income or expense that are equally earned or paid throughout the year (such as wages, interest, real estate taxes, etc) should use the annual average exchange rate. For 2012, the average annual exchange rates are:
NEW IRS RATES:
Other items of income or expense that are not earned or paid equally throughout the year (such as dividends, stock transactions, moving expenses, etc. ) should use the exchange rate on the day the income was received or the payment was made. You can use any large bank or online exchange rate calculator to determine the daily exchange rate. We use the Federal Reserve Bank rates.
FBAR, Form TDF 90-22.1, Report of Foreign Bank and Financial Accounts
The Department of the Treasury has set the following exchange rates for use on your 2012 FBAR: