Short answer. Your letter of acceptance binds the offeror only from the moment it actually comes to their knowledge — not when you mailed it, not when it arrived at their address. The Civil Code adopts the cognition theory: no contract forms until the offeror actually learns of your acceptance.
What the law says
Acceptance made by letter or telegram does not bind the offerer except from the time it came to his knowledge.
Civil Code, Article 1319 — Consent: Offer and Acceptance. Read the full provision →
The cognition theory: knowledge, not dispatch
Article 1319 of the Civil Code settles the question clearly for letters and telegrams: acceptance made by letter or telegram does not bind the offerer except from the time it came to his knowledge. The Philippines follows what is called the cognition theory — the contract is only perfected when the offeror actually knows that the offer has been accepted. This is stricter than the "mailbox rule" used in some other countries, where posting the letter is enough. Here, mailing, delivery to a mailbox, or even arrival at the offerer's office does not automatically form a contract if the offerer has not yet actually read or received the acceptance.
What this means if the offeror claims not to have received your letter
The cognition rule puts a practical burden on you as the accepting party: you should be able to prove not just that you sent the letter, but that the other side actually received it and came to know of its contents. Registry receipts, courier tracking records showing delivery, acknowledgment receipts, or a follow-up call or message confirming receipt are all evidence of the date the offeror gained knowledge. If the offeror denies having received your acceptance, a court would look at the circumstances — a letter sent to the correct address and not returned as undeliverable raises a reasonable inference of receipt, but the burden of proving knowledge is yours.
The acceptance must also be absolute
Even setting aside the timing issue, Article 1319 requires that the acceptance be absolute. If your letter said "I accept, but only if you lower the price by ten percent" or added any new condition, that is not an acceptance — it is a counter-offer, and the original offeror is now free to accept or reject it. A qualified acceptance does not form a contract; it effectively terminates the original offer and starts a new round of negotiation. Make sure your letter accepted the offer exactly as it was made, without additions or modifications.
Where the contract is formed
For contracts formed by letter or telegram, Article 1319 also provides that the contract is presumed to have been entered into in the place where the offer was made. This matters if a dispute ever arises about which court has jurisdiction or which local rules apply. If the offeror was in Manila when they made the offer, the contract is deemed made in Manila even if you accepted from Cebu. This is a presumption, not an absolute rule, and the parties are free to agree on a different venue in their contract.
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.
- Purificacion M. Vda. de Urbano, et al. vs. Government Service Insurance System (GSIS), et al, G.R. No. 137904, October 19, 2001 — read the decision on LawPhil →
- United Muslim and Christian Urban Poor Association, Inc., etc. vs. BRYC-V Development Corporation, etc., et al, G.R. No. 179653, July 31, 2009 — read the decision on LawPhil →
- Conchita Tan etc. vs. Planters Products Inc, G.R. No. 172239, March 28, 2008 — read the decision on LawPhil →
- Pedro Gonzales, et al. vs. Madame Pilar Farm Corp., et al, G.R. No. 115880, January 23, 2007 — read the decision on LawPhil →