The Legal Status of Uncertain Agreements in Contracts

A contract is only as strong as the certainty of its terms. If two parties cannot say, with reasonable confidence, what they actually agreed to buy, sell, or do, the law refuses to enforce that “agreement” at all. This is exactly the problem Section 29 of the Indian Contract Act, 1872 deals with. It sits quietly between the rules on unlawful consideration and wagering agreements, but it answers a question every business owner eventually runs into: how specific does a deal need to be before a court will actually stand behind it?

What section 29 actually says 🔗

Section 29 states that agreements whose meaning is not certain, or capable of being made certain, are void. Notice the two-part test buried in that line. An agreement is not automatically doomed just because it looks vague on the surface. It is only void if that vagueness cannot be resolved through interpretation, trade custom, or some objective external standard. If the uncertainty can be cleared up, the agreement survives. If it cannot, there is no contract to enforce, because a court cannot force parties to perform obligations nobody can actually define.

This idea traces back to a basic principle of contract law: courts interpret intention, they do not invent it. In Kovuru Kalappa Devara v Kumar Krishna Mitter, the courts made this distinction clear – an agreement should ideally be certain on its face, but effect can still be given to it if its meaning can be worked out with reasonable clarity from the surrounding facts. Only when that exercise fails does Section 29 step in to strike the agreement down.

The classic oil illustration 🔗

Textbooks almost always use the same example, and for good reason – it captures the whole idea in one line. If A agrees to sell B “a hundred tons of oil,” with nothing indicating which kind of oil is meant, the agreement is void for uncertainty, since there is no way to know what was actually intended. Contrast this with a near-identical scenario: A agrees to sell B a hundred tons of oil of a specified description that is already recognised as an article of commerce. Here there is no uncertainty at all, because the description itself pins down exactly what is being traded. The difference between a void agreement and a perfectly enforceable one can come down to a single missing word.

The two ways an agreement becomes uncertain 🔗

Vagueness under Section 29 generally shows up in one of two forms. Either the terms used are ambiguous – capable of more than one meaning – or the agreement is incomplete, missing something essential that was never filled in. As one detailed analysis of the section notes, an agreement may be uncertain either because its terms are vague or ambiguous, or because the agreement itself is incomplete. Both routes lead to the same legal dead end: a promise that cannot be pinned down cannot be enforced.

When the price itself is the problem 🔗

Uncertainty is not limited to the subject matter of a contract. Price clauses are just as vulnerable. Take the Section 29 illustration where A agrees to sell B “my white horse for rupees five hundred or rupees one thousand.” There is nothing in the agreement to indicate which of the two prices was actually intended, which makes the agreement void. This is a useful reminder for anyone drafting a commercial contract: an “or” clause without a mechanism to resolve it is not flexibility, it is a legal loophole that voids the whole deal.

How courts try to rescue an apparently vague agreement 🔗

Before declaring an agreement void, courts first ask whether the uncertainty can be resolved using tools outside the four corners of the document itself. Trade custom is one such tool. Where an industry has an established, well-understood usage for a term, that usage can be read into the contract even if the written words alone look ambiguous. As explained in the analysis of Section 29 case law, vagueness on the face of a contract can sometimes be resolved by referring to custom or trade usage, and phrases that appear vague to an outsider can be perfectly certain to someone familiar with that particular trade.

Courts also draw a firm line between an agreement that is genuinely indefinite and one that merely contains a minor, correctable ambiguity. If a delivery is scheduled for “four o’clock” without specifying morning or evening, that is not the kind of defect Section 29 is worried about. As one explanation of the provision puts it, this kind of minor ambiguity can usually be resolved without disturbing the core of the agreement, so the contract remains enforceable. The test is always about the essential terms – what is being sold, to whom, at what price, and on what conditions. Trivial gaps that context can easily fill do not sink an otherwise workable contract.

Letting the price be fixed later: market rate and third-party valuation 🔗

This is where the outline’s second half becomes important, and where students often get confused. Section 29 does not require every commercial detail to be nailed down at the moment of signing. Businesses routinely agree to deals where the final price is left open, to be determined later through an objective process. This kind of arrangement is valid precisely because it is capable of being made certain, even if it is not certain on day one.

The Sale of Goods Act, 1930, which works alongside contract law principles for the sale of goods, spells this out clearly. Price can be left to be fixed by a subsequent arrangement between the parties, by the ordinary course of dealing between them, or by prevailing market rates, and if no such arrangement is made, the buyer becomes liable to pay a reasonable price for the goods instead. This “reasonable price” fallback is exactly the kind of external, ascertainable standard that keeps an agreement out of Section 29’s reach.

Fixing price through an independent valuer 🔗

An even more structured version of this idea appears in Section 10 of the Sale of Goods Act, which deals with agreements to sell goods at a valuation to be fixed by a third party. The statute is direct on what happens if that valuer cannot or does not act: the agreement is avoided, though a buyer who has already received and appropriated the goods must still pay a reasonable price for them. If a party deliberately obstructs the valuation, the law does not let them benefit from that misconduct. According to one summary of Section 10, where the third party is prevented from making the valuation due to the fault of the buyer or seller, the party not at fault can sue the defaulting party for damages.

The logic underneath all of this is consistent with Section 29 itself. A price “to be fixed by a named valuer” or “at prevailing market rate on the date of delivery” is not vague – it is a formula, and formulas can always be solved. What Section 29 punishes is not open-endedness itself, but open-endedness with no method of closure.

Certain versus uncertain: a quick comparison 🔗

Why this matters beyond the exam 🔗

For anyone heading into business, sales, or contract management, Section 29 is not just an academic rule – it is a drafting checklist. Vague purchase orders, informal deals sealed over email with phrases like “usual price” without defining what that means, or agreements that leave critical terms to be “sorted out later” without any mechanism for doing so, all carry the same risk: a court may simply refuse to enforce them. The safer approach, and the one commercial contracts routinely use, is to either specify terms precisely or build in an objective method for determining them later, whether that is a market index, a named valuer, or an agreed formula.

Understanding this distinction also connects neatly to related provisions students encounter in the same unit, such as contingent contracts, where obligations depend on the happening of an uncertain future event but the contract itself is not vague about what that event is. The common thread across both areas is that Indian contract law tolerates uncertainty about outcomes, but not uncertainty about meaning.

What do you think? If you were drafting a supply contract where the exact market price of a raw material could not be predicted months in advance, would you rely on a third-party valuer, a market-rate clause, or some other mechanism to keep the agreement enforceable? And can you think of a everyday example, even outside business, where a seemingly clear promise turned out to be too vague to actually rely on?

References

1. https://indiankanoon.org/doc/1818467/
2. https://www.legalserviceindia.com/legal/article-16109-decoding-section-29-of-indian-contract-act-1872.html
3. https://blog.ipleaders.in/agreements-void-for-uncertainty-under-section-29/
4. https://www.tutorialspoint.com/uncertain-agreement-section-29-of-the-indian-contract-act-1872
5. https://blog.ipleaders.in/how-price-of-a-sale-is-determined-under-the-sale-of-goods-act-1930/
6. https://indiankanoon.org/doc/373967/
7. https://umeschandracollege.ac.in/pdf/study-material/busness-law/Sale%20of%20Goods%20Act%201930.pdf