In the Philippine decentralization framework, the local legislative bodies—the Sangguniang Panlalawigan (Province), Sangguniang Panlungsod (City), Sangguniang Bayan (Municipality), and Sangguniang Barangay—serve as the deliberative hearts of Local Government Units (LGUs). Their power to enact ordinances and resolutions is governed strictly by Republic Act No. 7160, otherwise known as the Local Government Code (LGC) of 1991. Central to their function are the rules governing their sessions, which ensure transparency, legality, and orderly governance.

1. The Internal Rules of Procedure (IRP)

Before any legislative business can truly commence, every Sanggunian is mandated to adopt or update its Internal Rules of Procedure within the first ninety (90) days of its first regular session following local elections.

The IRP serves as the "law of the house," covering:

The organization of the Sanggunian and the creation of standing committees.
The order and calendar of business.
The legislative process (how ordinances and resolutions are filed and debated).
The discipline of members for disorderly behavior or absences.

2. Regular Sessions: The Standard Rhythm

Regular sessions are the routine meetings where the Sanggunian performs its primary legislative duties.

Frequency: For Provinces, Cities, and Municipalities, the Sanggunian must hold a regular session at least once a week. For Barangays, the requirement is at least twice a month.
Schedule: The specific day, time, and place for these sessions are fixed by the Sanggunian through a resolution.
Public Access: As a general rule, sessions are open to the public. However, a "closed-door" or executive session may be held when the topic involves highly sensitive matters (e.g., national security, pending litigation, or personnel reputations).
Presiding Officer: The Vice Governor (for provinces) or the Vice Mayor (for cities and municipalities) acts as the Presiding Officer. In the Barangay, the Punong Barangay presides.

3. Special Sessions: Addressing the Urgent

When public interest or an emergency requires immediate legislative action, a special session may be called.

Who can call it: A special session may be called by the Local Chief Executive (Governor, Mayor, or Punong Barangay) or by a majority of the members of the Sanggunian.
Notice Requirement: A written notice must be served to each member of the Sanggunian, stating the date, time, and purpose of the session. This notice must be delivered at least twenty-four (24) hours before the session begins.
The "Agenda Only" Rule: This is a critical legal limitation. During a special session, the Sanggunian can only consider the specific items listed in the notice, unless the body, by a two-thirds (2/3) vote of the members present (there being a quorum), decides to consider other urgent matters.

4. Quorum and Voting

A session cannot validly transact business without a quorum.

Definition: A quorum is defined as a majority of all the members of the Sanggunian who have been elected and qualified.
The Presiding Officer's Role: In provinces, cities, and municipalities, the Vice Governor/Vice Mayor is not counted toward the quorum because they are not "members" of the body in the same sense as the elected councilors (they only vote to break a tie). However, in the Sangguniang Barangay, the Punong Barangay is a member and is counted.
Lack of Quorum: If a quorum is not met, the Presiding Officer may declare a recess until a quorum is reached, or a majority of those present may adjourn from day to day and compel the attendance of absent members.

5. Venue and Record-Keeping

Permanent Site: Sessions are generally held at the designated session hall within the LGU's seat of government.
Temporary Venue: The Sanggunian may, for a valid reason (e.g., a natural disaster or a public hearing in a specific locality), hold a session elsewhere within its jurisdiction via a formal resolution.
Journal of Proceedings: Every Sanggunian must maintain a Journal and Record of Proceedings. This must include the "ayes" and "nays" on any question, and the text of every ordinance and resolution passed. This record must be signed by the Secretary to the Sanggunian and attested by the Presiding Officer.

6. Legal Consequences of Non-Compliance

Actions taken by a Sanggunian in violation of these rules—such as passing an ordinance during a special session without proper 24-hour notice or without a valid quorum—are considered void ab initio (void from the beginning). Such acts have no legal effect and can be challenged in court or declared invalid by higher-level oversight bodies (e.g., the Sangguniang Panlalawigan reviewing a municipal ordinance).