Equitable Estoppel vs. Promissory Estoppel

Attribute	Equitable Estoppel	Promissory Estoppel
Definition	Prevents a party from asserting a legal right that contradicts their prior conduct or representations	Prevents a party from going back on a promise made to another party
Origin	Derived from principles of fairness and justice	Derived from contract law principles
Elements	1. Representation or conduct by the party2. Reliance on the representation or conduct by another party3. Detriment suffered by the relying party4. Injustice if the party is allowed to go back on their representation or conduct	1. Promise made by one party to another2. Reliance on the promise by the other party3. Detriment suffered by the relying party4. Injustice if the promisor is allowed to break the promise
Legal Basis	Based on principles of estoppel and equity	Based on principles of contract law and promissory estoppel

Introduction

Equitable estoppel and promissory estoppel are two legal doctrines that are often used in contract law to prevent injustice. While they both involve a promise or representation that is relied upon by one party to their detriment, there are key differences between the two concepts that are important to understand.

Equitable Estoppel

Equitable estoppel, also known as estoppel in pais, is a legal doctrine that prevents a party from asserting a right that they would otherwise have been entitled to assert. This doctrine is based on the principle that it would be unfair or unjust for a party to go back on their word or representation after another party has relied on it to their detriment.

Equitable estoppel typically arises when one party makes a promise or representation to another party, who then relies on that promise or representation to their detriment. In order for equitable estoppel to apply, the party asserting the estoppel must show that they reasonably relied on the promise or representation, and that it would be unfair or unjust for the other party to go back on their word.

One key aspect of equitable estoppel is that it is a defensive doctrine, meaning that it is typically raised as a defense in response to a legal claim or action brought by the other party. In other words, equitable estoppel is used to prevent a party from enforcing their legal rights when it would be unfair or unjust to do so.

Equitable estoppel is often used in cases where one party has made a promise or representation that induces another party to act in a certain way, and then seeks to renege on that promise or representation. By invoking equitable estoppel, the party who relied on the promise or representation can prevent the other party from going back on their word.

Overall, equitable estoppel is a powerful legal doctrine that can be used to prevent injustice and ensure fairness in contractual relationships. It is based on the principle that parties should be held to their promises and representations when others have relied on them to their detriment.

Promissory Estoppel

Promissory estoppel, also known as detrimental reliance, is a legal doctrine that prevents a party from going back on a promise that they have made, even if that promise is not supported by consideration. This doctrine is based on the principle that it would be unfair or unjust for a party to break their promise after another party has relied on it to their detriment.

Promissory estoppel typically arises when one party makes a promise to another party, who then relies on that promise to their detriment. In order for promissory estoppel to apply, the party asserting the estoppel must show that they reasonably relied on the promise, and that it would be unfair or unjust for the other party to break their promise.

One key aspect of promissory estoppel is that it is an offensive doctrine, meaning that it can be used as the basis for a legal claim or action against the party who made the promise. In other words, promissory estoppel can be used to enforce a promise that would otherwise not be legally binding due to lack of consideration.

Promissory estoppel is often used in cases where one party has made a promise that induces another party to rely on it to their detriment, and then seeks to break that promise. By invoking promissory estoppel, the party who relied on the promise can enforce it against the party who made the promise.

Overall, promissory estoppel is a valuable legal doctrine that can be used to enforce promises that would otherwise not be legally binding. It is based on the principle that parties should be held to their promises when others have relied on them to their detriment.

Key Differences

• Equitable estoppel is a defensive doctrine, while promissory estoppel is an offensive doctrine.
• Equitable estoppel is typically used to prevent a party from enforcing their legal rights, while promissory estoppel is used to enforce a promise that would otherwise not be legally binding.
• Equitable estoppel is based on the principle of fairness and justice, while promissory estoppel is based on the principle of detrimental reliance.
• Equitable estoppel requires a promise or representation to have been made, while promissory estoppel only requires a promise to have been made.
• Equitable estoppel is often used in cases where one party seeks to go back on their word, while promissory estoppel is used to enforce promises that have been relied upon.

Conclusion

While equitable estoppel and promissory estoppel are both legal doctrines that are used to prevent injustice in contractual relationships, they have key differences that are important to understand. Equitable estoppel is a defensive doctrine that prevents a party from enforcing their legal rights, while promissory estoppel is an offensive doctrine that can be used to enforce promises that would otherwise not be legally binding. Both doctrines are based on the principles of fairness and justice, and play a crucial role in ensuring that parties are held to their promises and representations when others have relied on them to their detriment.