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Ingenico: Estoppel Follows Grounds, Not Evidence

Federal Circuit, decided 7 May 2025. Read from the opinion; quotations verified against the court's text.

Read this with Caltech v. Broadcom. This decision bounds the forfeiture Caltech created. Read alone it sounds like estoppel barely matters, which is not true either.
Holding

On May 7, 2025 the Federal Circuit held that inter partes review estoppel "does not preclude a petitioner from asserting the same prior art raised in an IPR in district court" but rather bars the legal grounds that could have been raised there, so patents and printed publications remain usable as evidence for grounds an IPR could never have reached, such as prior public use or on-sale.

Inter partes review can only challenge a patent on published documents. So what happens to a defendant who loses an IPR and then wants to prove in court that the invention was already on sale or in public use?

The Federal Circuit held that estoppel attaches to the legal ground, not to the evidence, and that "prior art is evidence of a ground, not coextensive with a ground." The same document can be estopped in one argument and freely usable in another.

The other half of the decision shows how much the carve-out is worth in practice: a launch email, a press release, an archived downloads page and a user guide were enough to prove public use, with no witness who had ever used the product.

What This Case Is Not

This is not a general escape hatch. The rule is clean enough to invite reading it as a way around estoppel. It works only where the ground genuinely could not have been raised in an IPR, and the opinion does not say how courts will police attempts to recharacterize an estopped argument as an unestopped one.
  • It does not undo Caltech. The broad forfeiture on document-based grounds stands.
  • It does not say any particular ground escapes estoppel.
  • The evidence point cuts both ways: ordinary marketing artifacts proved public use here, which is worth knowing whichever side you are on.

Educational, not legal advice. Litigation strategy and exposure are determinations for counsel with the actual facts.

Sources