In the Philippines, while the obligation to pay valid debts remains, the law strictly prohibits debt collectors from using harassment, threats, or unfair practices to coerce payment. Debt collection is a legitimate business activity, but it must be conducted within the bounds of human dignity and legal protocols.

1. The Governing Law: SEC Memorandum Circular No. 18 (Series of 2019)

The primary regulation governing the conduct of debt collectors (specifically for financing and lending companies) is SEC Memorandum Circular No. 18. This circular explicitly lists "Prohibited Unfair Debt Collection Practices."

Prohibited Acts

Physical Violence or Threats: Any use or threat of physical force against the debtor, their reputation, or their property.
Obscene or Profane Language: Using insults or foul language to intimidate the borrower.
Disclosure of False Information: Threatening to share false credit information or claiming that non-payment will result in immediate arrest (debt is generally a civil matter, not criminal, except in cases involving Bouncing Checks/BP 22).
Harassment at Unreasonable Hours: Contacting the debtor before 6:00 AM or after 10:00 PM, unless the borrower has given express consent.
Contacting Third Parties: Disclosing the debtor's name or information to third parties, including social media shaming, except for contacts provided by the borrower as references.

2. The Data Privacy Act of 2012 (RA 10173)

Many abusive collectors use "contact-list grabbing" or social media shaming. These are severe violations of the Data Privacy Act.

Unauthorized Processing: Accessing your phone's contact list without explicit, informed consent is illegal.
Malicious Disclosure: Posting your debt details on Facebook or messaging your colleagues to shame you is a criminal offense under this Act.
Right to Object: You have the right to demand that a company stop processing your data if the methods used are unlawful or discovery of the debt is being publicized to harass you.

3. Revised Penal Code and Special Laws

Beyond administrative circulars, certain actions by collectors may fall under the Revised Penal Code (RPC):

Grave or Light Threats (Art. 282-283): Threatening to harm the debtor or their family.
Unjust Vexation (Art. 287): Any human conduct which, although not causing physical harm, unjustly annoys or irritates an innocent person.
Cyber Libel: If the harassment happens online (Facebook, Viber, etc.) and involves false or malicious imputations that diminish your reputation, it falls under the Cybercrime Prevention Act of 2012.

4. Can You Go to Jail for Debt?

The 1987 Philippine Constitution (Art. III, Sec. 20) states: "No person shall be imprisoned for debt."

However, there is a crucial distinction. While you cannot be jailed for the simple inability to pay a loan, you can face criminal charges if:

BP 22 (Bouncing Checks Law): You issued a check that was dishonored for insufficient funds.
Estafa (Art. 315, RPC): You used deceit or fraudulent misrepresentation to obtain the loan.

5. Step-by-Step Actions to Take

If you are a victim of harassment, follow these steps to build a legal case:

A. Document Everything

Screenshots: Capture all text messages, emails, and social media posts.
Call Logs & Recordings: Record the time, date, and phone numbers used. If possible, record the audio of the conversation (note: inform the caller you are recording to comply with the Anti-Wiretapping Act).
Identify the Agency: Demand the full name of the collector and the name of the agency they represent.

B. File a Formal Complaint

The Lending Company: Send a formal "Cease and Desist" letter to the company’s compliance officer.
SEC (Securities and Exchange Commission): File a complaint through the Corporate Governance and Finance Department (CGFD) for violations of MC No. 18.
National Privacy Commission (NPC): If they accessed your contacts or shamed you online, file a privacy violation complaint.
PNP Anti-Cybercrime Group: For death threats or severe online harassment.

6. Summary of Key Protections

Issue	Legal Basis	Penalty/Remedy
Nighttime Calls	SEC MC 18	Administrative Fines/License Revocation
Social Media Shaming	Data Privacy Act / Cyber Libel	Imprisonment and Fines
Threats of Violence	Revised Penal Code	Criminal Prosecution
Unauthorized Access to Contacts	Data Privacy Act	Cease and Desist / Criminal Charges

Legal Note: A debt does not give a collector the right to strip you of your privacy or dignity. Legitimate banks and lending apps are required to adhere to the "Fair Debt Collection Practices" as mandated by Philippine regulators.