For patent professionals challenging patents across Europe, the choice between EPO opposition and UPC revocation proceedings is one of the most consequential strategic decisions in modern IP litigation. Both forums offer powerful pan-European mechanisms, but each carries distinct advantages that must be carefully evaluated.

EPO opposition affects European patents across all relevant jurisdictions, while UPC revocation is confined to unitary patents or those not opted out — making EPO opposition the only viable route for patents outside the UPC's scope. A further complexity is the UPC's jurisdictional asymmetry: revocation actions are limited to UPC member states, yet infringement counterclaims may extend beyond them, creating meaningful exposure for both parties.

Forum selection should also reflect the nature of the case. The EPO's specialised examiners and rigorous doctrinal standards — particularly on added matter and inventive step — suit technically complex cases demanding precision and consistency. The UPC offers greater procedural flexibility, including expert cross-examination and a comparatively more permissive approach to added matter, making it better suited to cases where creative argumentation adds value.