The one possible escape
When a condition precedent has not been met, the law's default is unforgiving: no condition, no right. The main way to escape that is to argue the other party waived the condition, or is estopped from insisting on it - usually because its words or conduct led you to believe strict compliance was not required.
This is a genuine route, but a narrow one. It does not turn on your good intentions; it turns on what the other party said and did, and whether it would be unconscionable for them to insist on the condition now.
ISG Retail v FK: arguable, but uncertain
In ISG Retail Ltd v FK Construction Ltd [2024] EWHC 878 (TCC), a subcontract required notice of delay within fourteen days. The subcontractor's notices allegedly did not meet the clause's requirements, but it argued the contractor had waived strict compliance, or was estopped, because the parties had not been following the formal requirements in practice.
The court found there was an arguable case of waiver or estoppel with a real prospect of success - enough that the point could not be decided summarily and had to go to a full hearing. That cuts both ways: the escape route exists, but ISG Retail also shows how fact-heavy and unpredictable it is. You do not want your claim to depend on it.
When a condition "falls by the wayside"
Estoppel by convention is a related route. In the TCS v DBS litigation, the High Court found that one notice requirement - submission of draft reports within five working days - had fallen by the wayside, because both parties had proceeded on a shared, communicated assumption that it did not apply. That shared assumption created an estoppel preventing one side from later insisting on it.
So a condition can be eroded by how the parties actually behave. But that is a double-edged finding: the same conduct that frees one party from a condition can stop the other from enforcing it.
What you must show, and the trap
To establish waiver or estoppel you generally need clear evidence that the other party represented, by words or conduct, that strict compliance was not required; that you relied on that representation; and that it would be unconscionable for them to insist on compliance now. Courts will not infer waiver merely from a history of informality or flexibility.
The trap is on the enforcing side. If you are the party relying on a condition precedent, every extension you grant, every late submission you accept, every signal that timing is not critical can build the estoppel that defeats you when it finally matters. Flexibility is not free.
How to protect your position
If you want conditions enforced, enforce them consistently, and reserve your rights in writing when you do allow a one-off latitude, so a single indulgence does not become a course of dealing. If you are relying on waiver or estoppel, gather the contemporaneous evidence of the other side's words and conduct early - it is the whole case.
Above all, do not plan around waiver. It is a lifeboat, not a strategy. The reliable path is to satisfy the condition; the escape routes are narrow, costly to run, and uncertain.
Use at the desk
Practical checklist
- Treat waiver and estoppel as a narrow escape, not a plan - the reliable path is to satisfy the condition.
- To argue waiver or estoppel, show the other party's words or conduct, your reliance, and unconscionability (ISG Retail v FK [2024] EWHC 878 (TCC)).
- If you rely on a condition precedent, enforce it consistently - inconsistent practice can create estoppel by convention.
- Reserve your rights in writing whenever you allow a one-off latitude on a condition.
- Gather contemporaneous evidence early if you need to run a waiver or estoppel argument.
- In review, watch for a course of dealing that may have eroded a condition either side relies on.
This guide is informational only and is not legal advice. It does not replace advice from licensed counsel on the facts of a specific transaction.
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