In the Philippines, the power to exclude foreign nationals from entering the country is an exercise of sovereign prerogative. Under the Philippine Immigration Act of 1940 (Commonwealth Act No. 613), the State, through the Bureau of Immigration (BI), has the authority to control the entry and stay of aliens to protect public interest, safety, and order.

Filing a request to include a foreign national in the BI Blacklist is a formal administrative process governed by specific Department of Justice (DOJ) circulars and BI operations orders.

1. Legal Basis for Blacklisting

The primary authority lies with the Commissioner of Immigration. A foreign national is placed on the Blacklist (effectively becoming an excludable or prohibited alien) based on several grounds:

Violations of Immigration Law: Overstaying, working without a permit, or being undocumented.
Criminal Record: Conviction of a crime involving moral turpitude or being a fugitive from justice.
Public Threat: If the alien's presence is deemed inimical to local interest, public health, or safety.
Indigency: Being likely to become a public charge.
Other Lawful Requests: Requests from foreign governments (via Interpol) or private individuals with legitimate legal claims.

2. The Process: Filing a Letter-Petition

A private individual or entity (the "Petitioner") can initiate the blacklisting process by filing a formal request against a foreign national (the "Respondent").

Required Documentation

The petition must be verified and usually includes:

A Formal Letter-Request: Addressed to the Commissioner of Immigration, clearly stating the full name, known aliases, and passport details (if available) of the foreign national.
Affidavit of Complaint: A detailed narration of the facts justifying the blacklisting (e.g., details of a crime committed, breach of contract, or threatening behavior).
Supporting Evidence: Judicial records, warrants of arrest, police reports, or certified copies of court orders.
Filing Fees: Payment of the prescribed administrative and legal research fees at the BI.

3. Types of "Watch" Mechanisms

It is important to distinguish between the different lists maintained by the Bureau:

Blacklist Order (BLO): This is a permanent or long-term prohibition. Once a person is on this list, they are denied entry at all ports of entry or, if already in the country, are subject to deportation.
Alert List Order (ALO): This is often used for monitoring purposes or when there is an active investigation but not yet a final order for exclusion.
Watchlist Order (WLO): Usually issued in connection with pending criminal cases in Philippine courts, preventing the individual from leaving the country to ensure they face trial.

4. Due Process and Evaluation

The BI does not blacklist individuals based solely on a letter. The Legal Division of the Bureau evaluates the petition.

The Prima Facie Rule: The petitioner must establish a prima facie case that the alien is "undesirable."
Summary Deportation: If the alien is already in the Philippines and the grounds are clear (such as a foreign fugitive), the BI may issue a Summary Deportation Order (SDO) which automatically includes the alien in the Blacklist.
Inter-Agency Coordination: If the request involves national security or organized crime, the BI coordinates with the National Intelligence Coordinating Agency (NICA) or the DOJ.

5. Consequences of Being Blacklisted

Once an individual is officially on the Blacklist:

They are barred from entering Philippine territory.
If they attempt to enter, they are excluded at the airport and boarded on the next available flight to their point of origin.
Their name remains on the database across all international airports and seaports in the Philippines indefinitely, or until a formal Lifting Order is issued.

6. Remedies: Lifting and Removal

Blacklisting is not necessarily permanent, but "delisting" is a rigorous process. The foreign national must file a Petition for Removal from the Blacklist.

Lapse of Time: For certain violations, a specific number of years must pass before a request for removal is entertained.
Clearance: The petitioner must prove that the grounds for the original blacklisting no longer exist (e.g., the court case was dismissed, or the debt was paid).
Payment of Fines: All administrative fines and penalties must be settled.
Discretionary Approval: The final decision rests with the Commissioner of Immigration or the Secretary of Justice.

Summary Table: Blacklisting vs. Watchlist

Feature	Blacklist Order (BLO)	Watchlist Order (WLO)
Primary Goal	To prevent entry or deport.	To prevent exit (pending trial).
Target	Undesirable or illegal aliens.	Individuals with pending court cases.
Effect	Denial of entry at the border.	Stopped at the departure counter.
Authority	Bureau of Immigration.	Department of Justice / Courts.