Short answer. Yes. The Revised Penal Code makes it a crime to disobey a summons issued by Congress, its committees, or the Constitutional Commissions. Refusing without legal excuse to attend, to be sworn, to answer a legal inquiry, or to produce required documents is punishable, so a congressional summons is not something you can simply ignore.
What the law says
refuses, without legal excuse to obey such summons, or being present before any such legislative or constitutional body or official, refuses to be sworn or placed under affirmation or to answer any legal inquiry or to produce any books, papers, documents, or records in his possession
Revised Penal Code, Article 150 — Disobedience To Legislative Summons. Read the full provision →
What the offence covers
This provision punishes disobedience to summons issued by Congress, its committees and subcommittees, and the Constitutional Commissions. The conduct it reaches is broad. A person duly summoned as a witness commits the offence if he refuses, without legal excuse to obey such summons, and it does not stop at non-appearance. Even someone who shows up can fall within it by refusing to be sworn or placed under affirmation, refusing to answer a legal inquiry, or refusing to produce books, papers, documents, or records in his possession when required. The law also reaches anyone who shall induce disobedience to summons — encouraging a witness to defy the body is itself punishable.
The penalty, as amended in 2017
Be careful which version of the penalty you read. As amended by Republic Act No. 10951 (2017), which updated fines and monetary values throughout the Revised Penal Code, the punishment is arresto mayor or a fine ranging from Forty thousand pesos (₱40,000) to Two hundred thousand pesos (₱200,000), or both such fine and imprisonment. Older copies of the Code still print the original 1930 figures, which are far lower and no longer correct. If you are checking the exposure for defying a legislative summons, make sure the source you rely on reflects the 2017 amounts, not the pre-amendment ones.
The "legal excuse" qualifier matters
The crime punishes refusal without legal excuse. That phrase is important: not every refusal is criminal. A recognised legal ground for declining — for instance, a valid privilege against being compelled to answer a particular question — can be a legal excuse for that refusal. The distinction is between defying the summons outright and asserting a genuine, lawful basis for not answering a specific matter. Because the line between a protected refusal and a punishable one is technical and fact-specific, a person who intends to decline any part of a legislative inquiry should understand exactly which ground they are invoking and why it qualifies.
If you have been summoned
The safe course when a legislative or constitutional body summons you is to take it seriously rather than to gamble on ignoring it. Appearing does not mean surrendering every right; it means addressing the summons through proper channels and raising any valid objection or privilege in the right way, at the right time, rather than by simple defiance. If you have genuine reasons to resist attending, being sworn, answering, or producing documents, those reasons need to be assessed before you act on them. Bring the summons and the surrounding circumstances to a lawyer early, so any refusal you make rests on a real legal excuse and not a mistaken one.