Short answer. He does not get to decide forever. Article 1180 provides that when the debtor binds himself to pay when his means permit him to do so, the obligation is deemed to be one with a period — not a promise left to his goodwill — and the period can be judicially fixed.

What the law says

When the debtor binds himself to pay when his means permit him to do so, the obligation shall be deemed to be one with a period

Civil Code, Article 1180 — Payment 'When Means Permit'. Read the full provision →

A term, not a condition

The distinction the article draws is the whole answer. A condition is an uncertain event; a period is a stretch of time that will end. If when my means permit were read as a condition depending on the debtor's own will, the promise would be worth nothing — Article 1182 makes a conditional obligation void where fulfilment depends upon the sole will of the debtor. Article 1180 refuses that outcome. The debt is real and already owing; what is open is only when it must be paid, and the debtor's reluctance is not what settles that.

Asking the court to fix the time

Because the parties never named a date, somebody has to. The article routes the question to the rules on obligations with a period, under which a court may fix the duration the parties evidently intended, having regard to the circumstances — the size of the debt, what the debtor does for a living, what was said when the note was signed. It is a real step and it takes time, so a creditor should understand that the immediate demand may be for the period to be set rather than for payment on the spot. Once fixed, the date binds both sides.

When the debtor loses the benefit of time

Article 1198 lists the situations in which a debtor forfeits the period altogether: when he becomes insolvent after contracting the obligation, unless he gives security; when he fails to furnish the securities he promised; when he impairs those securities by his own acts, or they disappear through fortuitous event and he does not replace them; when he violates the undertaking for which the creditor agreed to the period; and when he attempts to abscond. Any of these makes the debt demandable at once, whatever the wording of the note.

What to do with the IOU you have

Keep the original — the exact wording is what brings Article 1180 into play, and a note saying the debtor will pay when able is in far better shape than a vague acknowledgment. Make a written demand anyway, because under Article 1169 those obliged to deliver or to do something incur delay from the time the creditor judicially or extrajudicially demands fulfilment. And record what you know of his circumstances: property acquired, business resumed, travel, purchases. Means are proved by conduct, and the same evidence supports both fixing the period and enforcing it.

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.