Suinno Mobile & AI Technologies Licensing v Microsoft (CoA, 24 February 2026)

Dhenne Avocats · 10 October 2026

Our analysis

Summary

By decision of 24 February 2026 in the joined proceedings UPC_CoA_883/2025 and UPC_CoA_892/2025, the Court of Appeal (Panel 2) rejected Suinno’s applications for rehearing of its security for costs order and its default decision of 12 July 2025, which had dismissed the infringement action on EP 2 671 173 after Suinno failed to provide security of EUR 300,000. The decision underlines that rehearing is exceptional: disagreement with the reasoning or the outcome is not enough.

Question

Do an allegedly undecided alternative request for reduced security and an allegedly wrong reading of Rule 355 amount to a fundamental procedural defect under Article 81(1) UPCA and Rule 247?

Decision

Court of Appeal decisions are final. Rehearing is an extraordinary remedy that requires a defect so serious as to be intolerable for the legal system and proof that the decision would have been different without it, while the assessment of arguments and evidence is not reviewable (paragraph 13). Under Rule 248.1 the objection must have been raised in the original proceedings where possible: Suinno could raise its points in the security proceedings, and did so (paragraphs 15 to 19). The alternative request for EUR 100,000 was not overlooked: the Court assessed the amount within the range of EUR 100,000 to 300,000 (paragraph 20). A default decision is the enforcement mechanism provided by Rule 158.5 where security is not provided, and a party must comply with an order while challenging it (paragraphs 21 and 22). The applications and the request for suspensive effect were rejected, and Suinno bears the costs of the rehearing proceedings (paragraphs 24 to 26).

Key points for practice

• Rehearing is not a third instance: the defect must be fundamental, decisive and, where possible, objected to in the original proceedings (paragraphs 13 and 15).
• Failure to provide security for costs exposes a party to a default decision, even while the order is being challenged (paragraphs 21 and 22).

Provisions applied

Agreement on a Unified Patent Court

Arts 76(2) and 81(1)

Rules of Procedure

Rules 158.4, 158.5, 245, 247, 248.1, 252, 350 and 355

Case law cited

Alexion v Amgen, Court of Appeal, 19 June 2025 (UPC_CoA_405/2024), Alexion v Samsung, Court of Appeal, 19 June 2025 (UPC_CoA_402/2024), Ballinno v Kinexon, Court of Appeal, 26 August 2024

Related decisions

• Suinno v Microsoft, 12 July 2025, security for costs order challenged by the rehearing application.
• Microsoft v Suinno, 12 July 2025, default decision challenged by the rehearing application.

Prepared by Dhenne Avocats from the official decision, consulted on 10 October 2026. The database is updated every week, on Friday. Only the official text is authoritative.