In the Philippine democratic framework, the stability of local government units (LGUs) is paramount. To prevent a vacuum in leadership and ensure the continuous delivery of public services, the Local Government Code of 1991 (Republic Act No. 7160) establishes a self-executing mechanism for legal succession. These rules dictate how vacancies in elective offices—from the provincial Governor down to the Sangguniang Barangay—are filled by operation of law.

I. Permanent Vacancies: Causes and Definitions

A permanent vacancy arises when an elective local official fills a higher office, refuses to assume office, fails to qualify, dies, resigns, is removed from office by final judgment, or is permanently incapacitated for physical or mental reasons.

II. The Hierarchy of Succession

The law distinguishes between the executive leadership (Governor, Mayor, Punong Barangay) and the legislative bodies (Sangguniang Panlalawigan, Panlungsod, Bayan, and Barangay).

1. The Executive Offices

For the positions of Governor, City Mayor, or Municipal Mayor, the rule of automatic succession applies:

Governor: Succeeded by the Vice-Governor.
City/Municipal Mayor: Succeeded by the Vice-Mayor.
Punong Barangay: Succeeded by the highest-ranking Sangguniang Barangay member (the one who garnered the highest number of votes in the preceding election).

In the event that the successor (e.g., the Vice-Governor) also becomes permanently vacant, the next highest-ranking Sanggunian member assumes the office.

2. The Sanggunian (Legislative Councils)

Succession within the local councils follows a ranking based on the number of votes obtained in the last election.

If a permanent vacancy occurs in the Sangguniang Panlalawigan, Panlungsod, or Bayan, the rule is governed by Section 45 of RA 7160:
The Ranking Rule: The Sanggunian member who obtained the highest number of votes among those belonging to the same political party as the predecessor is elevated.
The Successive Shift: If the highest-ranking member moves up to a higher office (e.g., Vice-Mayor), the second-ranking member moves to the first, and so on.

III. Filling Vacancies via Appointment

While executive offices are filled by automatic succession, a "gap" is often left at the bottom of the legislative ladder. These remaining vacancies are filled via appointment:

Provincial and Highly Urbanized Cities: The President, acting through the Executive Secretary, appoints the successor.
Component Cities and Municipalities: The Governor appoints the successor upon the recommendation of the Sangguniang Panlalawigan.
Sangguniang Barangay: The City or Municipal Mayor appoints the successor upon the recommendation of the Sangguniang Barangay.

The Political Party Rule: To respect the mandate of the electorate, the appointee must come from the same political party as the official who caused the vacancy. A certificate of membership/nomination from the highest official of that political party is a mandatory requirement. If the official did not belong to a political party (independent), the appointer may choose any qualified person who meets the legal requirements for the office.

IV. Temporary Vacancies

A temporary vacancy occurs when an official is unable to perform duties due to physical or mental reasons, is on leave of absence, or is on official travel for more than three days.

Automatic Assumption: The Vice-Governor or Vice-Mayor automatically exercises the powers and performs the duties of the local chief executive, except the power to appoint, suspend, or dismiss employees, which can only be exercised after thirty (30) working days.
Termination: Temporary incapacity terminates upon submission of a written notice to the Sanggunian by the local chief executive concerned, signifying that they have reassumed their functions.

V. Special Rules and Prohibitions

Succession in the Sangguniang Kabataan (SK): Following the SK Reform Act (RA 10742), vacancies in the SK Chairperson position are filled by the SK member who obtained the highest number of votes. If a vacancy occurs in the SK council, the candidate who obtained the next highest number of votes in the last election is elevated.
The "Last Man Standing" Rule: In cases where all elective officials are vacant, the President may appoint an Officer-in-Charge (OIC) to ensure the LGU continues to function until a special election is called or the next regular election takes place.
Prohibited Appointments: No appointment shall be made to fill a vacancy in the Sanggunian within ninety (90) days immediately preceding a regular local election.

Summary Table: Succession and Appointment Authority

Position Vacated	Successor / Appointing Authority	Basis/Requirement
Governor	Vice-Governor	Automatic Succession
Mayor	Vice-Mayor	Automatic Succession
Vice-Governor/Mayor	Highest Ranking Sanggunian Member	Ranking by Votes
Sanggunian (Provincial)	President of the Philippines	Party Nomination
Sanggunian (City/Mun)	Governor	Party Nomination
Sanggunian (Barangay)	City/Municipal Mayor	Sangguniang Recommendation