Short answer. Possibly, but only if you knew. The third paragraph of Article 172 of the Revised Penal Code punishes a person who knowingly introduces a false document in evidence in a judicial proceeding. Someone who used a document in honest ignorance of the forgery is outside it.
What the law says
Any person who shall knowingly introduce in evidence in any judicial proceeding or to the damage of another or who, with the intent to cause such damage, shall use any of the false documents
Revised Penal Code, Article 172 — Falsification By A Private Individual. Read the full provision →
Using is a separate offence from forging
The law treats the forger and the user as two different offenders. The first two paragraphs of Article 172 punish the person who actually falsified the document. The third punishes the person who used it — either by knowingly introducing it in evidence in a judicial proceeding, or by using it to the damage of another or with the intent to cause damage. The user is punished by the penalty next lower in degree than the falsifier. So it is no answer to say you did not write a word of it; but equally, being the one who handed it up does not make you the forger.
'Knowingly' is the element that decides it
Everything turns on that one adverb. If you genuinely believed the document was authentic — you received it from a relative, a broker, an agency or a former employer and had no reason to doubt it — the paragraph is not met. But knowledge rarely comes as a confession. It is drawn from circumstances: whether you were the one who benefited, whether you were told of a problem and used the document anyway, whether the defect was obvious on the face of the paper, whether you can say where the document came from, and whether your account of its origin has stayed consistent. Vagueness about provenance is what usually sinks people.
The penalty and the current fine
For the falsification itself the article imposes prisión correccional in its medium and maximum periods and a fine of not more than one million pesos, and the user is punished one degree lower. That one-million-peso ceiling was set by Republic Act No. 10951 (2017), which revised fines and property values throughout the Revised Penal Code — reproductions printed before 2017 still carry the original, far smaller figure and should not be relied on. Where the document was used to obtain money or property, a separate estafa charge commonly accompanies the falsification count, and each is analysed on its own elements.
What to do now
Two things matter most, and both are about the trail. Preserve every message, receipt or transmittal showing how the document reached you and who gave it to you — that chain is the whole of your defence on the element of knowledge. And take advice before filing any further pleading or affidavit in the case, because an explanation given carelessly can supply the very knowledge the prosecution needs. Do not attempt to retrieve, alter or substitute the document already on record. Volunteering the problem to the court through counsel is usually far better than waiting for the other side to raise it. No outcome can be promised.