The doctrine of promissory estoppel, which prevents a party from going back on a promise that another party has relied upon to their detriment, should generally be applied to past promises in India. While the doctrine is not explicitly codified in Indian law, it has been recognized by the Supreme Court and used to protect individuals and businesses from unfair dealings.

The doctrine of promissory estoppel in India, as derived from English common law, prevents a party from going back on a promise made if the other party has relied on it to their detriment. Currently, Indian law (following Section 25 of the Indian Contract Act, 1872 and judicial precedents like *Union of India v. Anglo-Afghan Agencies, 1968*) applies promissory estoppel primarily to future-oriented promises, not past consideration.

The question is whether India should extend this doctrine to past promises—i.e., situations where a promise was made after the promisee has already acted in reliance on an earlier understanding.

Arguments in Favor of Extension
Equity and Fairness

If a party has already acted based on a reasonable expectation (even if no formal promise existed at the time), justice demands protection against unfair denial.

Example: If a government informally assures a business of tax exemptions, and the business invests heavily, but the government later reneges, estoppel should apply even if the promise was made after the initial investment.

Judicial Trends in Other Jurisdictions

Some common law jurisdictions (e.g., Australia, Canada) have relaxed the strict requirement of a pre-existing promise in estoppel cases.

The U.S. recognizes "detrimental reliance" even without a prior clear promise (Restatement (Second) of Contracts § 90).

Preventing Unjust Enrichment

If a party knowingly benefits from another’s actions based on an implied understanding, allowing them to later deny liability would be unjust.

Arguments Against Extension
Contractual Certainty

Indian contract law emphasizes offer, acceptance, and consideration (Section 2(d) of ICA, 1872). Extending estoppel to past promises could blur the line between contractual obligations and moral expectations.

Judicial Overreach

Courts may end up enforcing informal understandings that were never intended to be legally binding, increasing litigation.

Potential for Abuse

Businesses or individuals could claim "implied promises" after the fact, leading to frivolous claims.

Possible Middle Ground
Limited Extension: Courts could apply estoppel to past promises only where:

There was clear and unequivocal conduct creating a reasonable expectation.

The reliance was foreseeable and substantial.

Denial of the promise would cause grave injustice.

Conclusion
While extending promissory estoppel to past promises could enhance fairness, it must be done cautiously to avoid undermining contractual certainty. Indian courts could adopt a case-by-case approach, similar to developments in other common law jurisdictions, ensuring that estoppel remains an equitable remedy rather than a general contract law principle