This document contains temporary Income Tax Regulations relating to a United States taxpayer's obligation under section 905(c) of the Internal Revenue Code (Code) to notify the IRS of a foreign tax redetermination, which is a change in the taxpayer's foreign tax liability that may affect the taxpayer's foreign tax credit. This document also contains temporary Procedure and Administration Regulations under section 6689 relating to the civil penalty for failure to notify the IRS of a foreign tax redetermination as required under section 905(c). These temporary regulations affect taxpayers that have paid foreign taxes which have been redetermined and provide guidance needed to comply with statutory changes made to the applicable law by the Taxpayer Relief Act of 1997 and the American Jobs Creation Act of 2004. The text of the temporary regulations also serves as the text of the proposed regulations (REG-209020-86) set forth in the notice of proposed rulemaking on this subject published elsewhere in this issue of the Federal Register.