When are "entire agreement" clauses invalid?

Question

Contracts often include an "entire agreement" clause (a.k.a. "integration" or "merger" clause) like this:

This contract contains the final and entire agreement and understanding between the Parties and is the complete and exclusive statement of its terms. This contract supersedes all prior agreement and understandings, whether oral or written, in connection therewith.

This sounds like it would limit litigation regarding such an integrated contract to only (a) interpretations of the contract language or (b) factual questions of performance of the contract terms.

However this review claims:

[U.K.?] case law has established four specific limitations to entire agreement clauses:

1. Implied terms are not excluded
2. Liability for misrepresentation is not excluded
3. Mistakes can still be rectified
4. “Estoppel by convention” can still be invoked

Is this a complete and correct list of exceptions that apply to integration clauses in U.S. jurisdictions?

Answer 1

Is this a complete and correct list of exceptions that apply to integration clauses in U.S. jurisdictions?

No (neither it is for the UK or any other common law jurisdictions).

No matter to what extent "entire" are the clauses, they never contract out of the underlying law (unless the law expressly allows so). Instead, contracts specify what the law does not.

What that means is that there will always be terms that just come with the law and that contracts do not mention. Those 4 "exceptions" are just some examples. To get an idea of some more, one can just open a contract law course and see all those principles/doctrines established in case law over centuries. Unless invalidated by statute, they still are perfectly valid for the purposes of litigation over contracts with "entire agreement" clauses.