Short answer. Under the Civil Code's original text, a deaf-mute who cannot write was listed among those who cannot give valid consent. However, that provision predates current law on legal capacity — today, the analysis goes beyond the ability to write, and a deaf-mute person who can communicate meaningfully is not automatically barred from contracting. The answer depends on the specific circumstances.
What the law says
The following cannot give consent to a contract: (1) Unemancipated minors; (2) Insane or demented persons, and deaf-mutes who do not know how to write.
Civil Code, Article 1327 — Who Cannot Give Consent. Read the full provision →
What the Civil Code originally said
Article 1327 of the Civil Code lists persons who cannot give consent to a contract: unemancipated minors; insane or demented persons; and deaf-mutes who do not know how to write. The text reflects the era in which it was drafted. A deaf-mute person who had no ability to sign documents was treated as unable to express a reliable contractual intent. A contract entered by someone in that position was not void but voidable — meaning it could be annulled on the ground of incapacity.
How the law has changed
This article has been partly overtaken by later law. The age of majority reference assumed in number (1) was lowered from 21 to 18 by Republic Act No. 6809, so the class of unemancipated minors is now narrower. More importantly, the article's treatment of deaf-mutes who cannot write predates the present legal and social understanding of capacity. A person who is deaf and mute but can communicate through sign language, written text on a phone, or other means is not automatically incapacitated. Capacity is now assessed more functionally — can the person understand the nature and consequences of what they are agreeing to?
What actually matters for a valid contract
The core requirement for valid consent under the Civil Code is that the party understands what they are agreeing to and freely assents to it. A deaf-mute person who communicates fluently through sign language or assistive technology, understands the terms of a deal, and expresses their agreement clearly can enter a valid contract. The inability to physically write a signature is separate from the ability to consent. Contracts today may be executed with thumbmarks, witnessed by a notary, or signed through other authenticated means. What the law guards against is a situation where the person genuinely cannot comprehend or express meaningful agreement.
Practical precautions
If you are contracting with or on behalf of a deaf-mute person, take care to ensure the process is genuinely understood. Use a qualified sign language interpreter if the person communicates in sign language, and have that fact noted in the document. A notarized instrument with the interpreter's attestation provides a stronger record. If the person's capacity is uncertain — because of additional cognitive limitations, for instance — have a guardian involved and, if necessary, seek a court order authorizing the transaction. Document everything that shows the person understood and freely agreed.
Cases citing this provision
These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.
- Samahan ng Magsasaka sa San Josep, et al. vs. Marietta Valisno, et al, G.R. No. 158314, June 3, 2004 — read the decision on LawPhil →