Short answer. Yes, once the buyer is in delay. Article 2209 provides that where the obligation is to pay a sum of money and the debtor incurs delay, the indemnity for damages, absent a stipulation to the contrary, is the interest agreed upon, and in the absence of stipulation, the legal interest.
What the law says
the indemnity for damages, there being no stipulation to the contrary, shall be the payment of the interest agreed upon, and in the absence of stipulation, the legal interest, which is six per cent per annum
Civil Code, Article 2209 — Interest on Money Obligations. Read the full provision →
Delay is the trigger, and lateness alone is not delay
Article 1169 provides that those obliged to deliver or to do something incur in delay from the time the obligee judicially or extrajudicially demands from them the fulfilment of their obligation. So in the ordinary case interest under Article 2209 does not begin running on the due date; it begins when you demand and he still does not pay. Article 1169 also sets out the situations where no demand is needed — where the obligation or the law expressly says so, where the time fixed was a controlling motive for the contract, and where demand would be useless. Otherwise, make the demand.
Which rate applies
The article says the indemnity is the payment of the interest agreed upon, and in the absence of stipulation, the legal interest, which is six per cent per annum. Two things follow. If your contract had named a rate, that rate would govern; because it is silent, the legal rate fills the gap. And the legal rate is a figure fixed by law rather than a term of your bargain, so neither party adjusts it to taste. It has also been the subject of regulation outside the Code, so confirm the rate applicable to your period instead of assuming one number covers every year the debt has run.
You do not have to prove what the delay cost you
Notice how the article frames it: the interest is the indemnity for damages. That is a substitute for proof, so you need not show a missed opportunity or a loan you had to take out to cover the gap. The law fixes what a delayed money obligation is worth. The corollary is that this head of loss is measured by the interest rather than by the strength of your grievance, so a seller who wants more is looking for a different provision and a different kind of proof. Article 2210 separately leaves interest upon damages awarded for breach of contract to the court's discretion.
Make the demand, and date it
Because the running of interest depends on delay, the single most valuable document is a dated written demand that identifies the amount and asks for payment. Send it in a way that proves receipt, and keep the proof. Alongside it keep the contract or purchase order, the invoices, the delivery records and the account of what has been paid so far, since interest is computed on a principal that must be established first. If the buyer disputes the amount rather than the timing, deal with that early: interest on a contested figure is an argument stacked on an argument.
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.
- Lara’s Gifts & Decors, Inc. vs. Midtown Industrial Sales, Inc, G.R. No. 225433, August 28, 2019 — read the decision on LawPhil →
- S.C. Megaworld Construction and Development Corporation vs. Engr. Luis U. Parada, represented by Engr. Leonardo A. Parada of Genlite Industries, G.R. No. 183804, September 11, 2013 — read the decision on LawPhil →
- Republic of the Philippines, represented by the Department fo Public Works and Highways, G.R. No. 211666, February 25, 2015 — read the decision on LawPhil →
- Ece Realty & Development, Inc. vs. Haydyn Hernandez, G.R. No. 212689, August 6, 2014 — read the decision on LawPhil →