Vacancy Filling in Philippine Congress

Republic Act No. 6645 establishes the procedure for filling vacancies in the Senate and House of Representatives through a special election when the vacancy arises within specified time limits before the next regular election.

A vacancy in the Senate triggers Republic Act No. 6645 if it arises at least eighteen (18) months before the next regular election for Members of Congress.
A vacancy in the House of Representatives triggers Republic Act No. 6645 if it arises at least one (1) year before the next regular election for Members of Congress.
The Commission on Elections holds a special election only upon receipt of a certification and call for a special election by the proper chamber.
The elected Senator or Member of the House of Representatives serves only for the unexpired term.

When a qualifying vacancy arises, the Commission on Elections acts upon receipt of a resolution of the Senate or the House of Representatives, as the case may be, certifying the vacancy and calling for a special election.
If Congress is in recess, the President of the Senate or the Speaker of the House of Representatives, as the case may be, may send an official communication certifying the existence of the vacancy and calling for a special election, which is sufficient for purposes of initiating the special election.

The Commission on Elections fixes the date of the special election.
The special election date must be not earlier than forty-five (45) days nor later than ninety (90) days from the date of the resolution or official communication.
The Commission on Elections must state the office or offices to be voted for in fixing the special election date.
If a general election is scheduled within the relevant period, the special election is held simultaneously with the general election.

The Commission on Elections sends copies of the chamber resolution to the Provincial or City Treasurer of each province or city concerned, in a number sufficient for due distribution and publication.
The Provincial or City Treasurer must publish the resolution in the locality by posting at least three (3) copies in as many conspicuous places in each of the election precincts.
The Provincial or City Treasurer must also post a copy in each of the polling places and public markets, and a copy in the municipal buildings.