Suinno Mobile & AI Technologies Licensing v Microsoft (CoA, 7 April 2026)

Dhenne Avocats · 10 October 2026

Our analysis

Summary

By order of 7 April 2026, the Court of Appeal orders Suinno Mobile & AI Technologies Licensing, proprietor of EP 2 671 173, which the Paris Central Division revoked in its entirety, to provide Microsoft with security of EUR 600,000 for the costs of the appeal within three weeks, failing which a decision by default may be given. It holds inadmissible the request for security for first-instance costs, which had already been fixed by a costs decision, and refuses to stay the appeal. The order consolidates the Court’s case law on Art. 69(4) UPCA: on appeal only the respondent may seek security, even if it was the defendant at first instance, and once first-instance costs have been fixed, security for those costs is no longer available.

Facts and procedure

Suinno sued Microsoft for infringement before the Paris Central Division. Microsoft counterclaimed for revocation. As Suinno failed to provide the security ordered in the infringement action, a decision by default was given and the action was finally dismissed. Suinno has not paid the EUR 350,000 in costs awarded against it on 6 November 2025 (paragraphs 2, 3 and 25). On 7 January 2026 the central division revoked the patent in its entirety on the counterclaim (UPC_CFI_433/2024), and Suinno appealed (paragraphs 4 and 5). On 24 March 2026 Microsoft applied for security of EUR 1,200,000 for both instances, or alternatively EUR 600,000, and for a stay of the appeal (paragraph 6). On 31 March 2026 the central division fixed the costs of the counterclaim at EUR 300,000 (paragraphs 7 and 20).

The applicable law

Art. 69(4) UPCA allows security for costs to be ordered against the applicant, that is, the party that brings the proceedings (paragraph 14). Rule 158 governs the procedure and provides that, if security is not provided, a decision by default may be given (Rules 158.5 and 355). Rule 295(m) permits a stay where the proper administration of justice so requires, and Rule 9.3(a) the extension of a time limit on a reasoned request.

Question

May the respondent, the successful counterclaimant at first instance, obtain security for the costs of the appeal and for first-instance costs, and does the appellant’s financial position justify staying the appeal?

Decision

The Court recalls that at first instance the infringement claimant cannot obtain security, even against a counterclaim for revocation (paragraph 15). On appeal the appellant is the applicant: only the respondent may seek security, even if it was the claimant below (paragraph 16), because the appellant has chosen to challenge a decision presumed to be correct, save for a manifest error, which Suinno has not shown (paragraphs 17 and 18). The request relating to first-instance costs is inadmissible once a costs decision has been issued. Any challenge must go through an application for leave to appeal (paragraphs 19 to 21). Non-payment of the infringement costs and the unchallenged admission of insufficient means give rise to a real and legitimate concern that costs will not be recoverable (paragraphs 23 to 26). The end of the infringement action does not deprive the counterclaim of its object, as Rule 265.2 shows (paragraph 27). The amount of EUR 600,000, the applicable ceiling, is not disputed (paragraphs 28 and 29). The stay is refused: security already protects the respondent and every party is entitled to expeditious proceedings (paragraphs 35 to 39). The time limit for the statement of response is extended to 19 June 2026, as an exceptional measure (paragraphs 40 and 41).

Key points for practice

• On appeal, security under Art. 69(4) UPCA may only be sought by the respondent, whatever its position at first instance (paragraph 16).
• Once first-instance costs have been fixed, security for those costs is inadmissible. The only route is an application for leave to appeal (paragraphs 20 and 21).
• An appellant’s financial difficulties justify security, not a stay (paragraphs 36 to 39).
• Practical point: a respondent facing an appellant that has not paid earlier costs should apply promptly for security for the appeal, together with an extension of its own time limit to respond (paragraphs 25, 26 and 41).

Provisions applied

Agreement on a Unified Patent Court

Arts 32(1)(d) and 69(4)

Rules of Procedure

Preamble and Rules 9.3, 150, 158, 265.2, 295, 311 and 355

Case law cited

Hefei v Grundfos, Court of Appeal, 19 December 2025, on the meaning of applicant and security on appeal, AorticLab v Emboline, Court of Appeal, 20 June 2025, on the unavailability of security for a claimant at first instance, Oerlikon v Bhagat, Court of Appeal, 30 October 2025, on inadmissibility after a costs decision and the risk test, Belkin v Philips, Court of Appeal, 29 October 2024, on manifest error.

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.