District of Columbia House Voting Rights Act of 2007 - Considers the District of Columbia a congressional district for purposes of representation in the House of Representatives.
Applies to the District in the same manner as it applies to a state the federal law providing for the fifteenth and subsequent decennial censuses and for apportionment of Representatives in Congress. Limits the District to one Member under any reapportionment of Members.
Modifies the formula regarding the number of presidential electors to subject it to the Twenty-Third amendment to the Constitution in the case of the District.
Increases membership of the House from 435 to 437 Members beginning with the 110th Congress and each succeeding Congress.
Provides for a reapportionment of Members resulting from such increase.
Prescribes a procedure for identifying the additional Representative to which a state other than the District of Columbia shall be entitled under this Act. Requires election at large of such additional Representative.
Amends the Internal Revenue Code to increase (from 110% to 110.1%) the estimated tax payment safe harbor percentage for determining the amount of estimated tax payable by individual taxpayers whose adjusted gross income for the preceding taxable year exceeds $5 million.