Short answer. Article 1956 itself only requires that interest be expressly stipulated in writing for it to be due at all — it does not fix what rate applies when the writing is silent on the number. That gap is a separate question this specific article does not answer.

What the law says

No interest shall be due unless it has been expressly stipulated in writing.

Civil Code, Article 1956 — Interest Must Be Stipulated in Writing. Read the full provision →

What Article 1956 actually requires

Article 1956 sets a threshold condition, not a rate schedule. No interest shall be due unless it has been expressly stipulated in writing. Its function is to bar interest from being owed at all unless the parties put their agreement to pay it in writing — a purely verbal understanding to pay interest is not enough under this article, regardless of what rate might have been discussed. Your note satisfies the writing requirement in the sense that it is in writing and mentions interest.

Whether a rate-less clause counts as 'expressly stipulated' is a separate question

The harder question your note raises is whether a written promise to pay interest, without stating how much, actually amounts to interest being expressly stipulated within the meaning of this article. Article 1956 does not resolve that question itself — it establishes the writing requirement in general terms and does not walk through what counts as sufficiently express when a key term like the rate is left blank.

This article does not supply a default rate

It is worth being precise about what Article 1956 does not do: it does not name a percentage, a legal rate, or any numerical default that fills in for a missing rate. Any specific figure you may have heard referenced as a fallback interest rate comes from provisions and legal principles outside this article, and this page will not state a number here that is not drawn from the verified text of Article 1956 itself.

What this means for your note

Because the rate is missing, the practical question is whether your note's general promise to pay interest is treated as an express stipulation at all, and if so, what fills the gap on the actual rate — both of which require looking beyond this single article. Reviewing your promissory note together with whatever other terms it contains, and getting advice on how the missing rate is actually treated, is a more reliable path than assuming any particular figure applies by default.

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.

Related provisions

Note. Statute text quoted on this page is reproduced from the official enactment and is linked to the full provision. The explanation around it is general legal information from Vivas & Nobles Law Office, not legal advice. Whether it applies to your situation depends on facts only a lawyer reviewing them can assess.