InterDigital, Inc & Ors v Optis Cellular Technology LLC & Ors

Redaction of a judgment is governed by one fact-sensitive question: whether, in the circumstances, the interests of justice require open justice to yield. A strong presumption of publicity remains. Redaction requires powerful reasons supported by cogent, specific evidence. The wide statutory definition of a trade secret does not automatically determine the issue.

In FRAND litigation, lump-sum and per-unit royalty data may have equal commercial sensitivity. Both should be redacted where publication would cause real competitive harm or enable redacted figures to be inferred, while enough reasoning should remain public for the judgment to be understood. An accidental slip or omission may be corrected under the slip rule, including on a third party’s initiative.

Optis and Apple litigated the terms of a FRAND licence concerning standards-essential patents. The High Court’s full judgment contained third-party licence terms. After a public version was issued, third parties made confidentiality representations. Marcus Smith J ordered publication of a less-redacted judgment in [2024] EWHC 197 (Ch), retaining redactions for lump-sum figures but disclosing per-unit figures, derived data and some licence descriptions.

Third-party licensors and licensees appealed. Apple also appealed concerning aggregate figures and information relating to non-appealing counterparties. The Court of Appeal considered the proper approach to confidential redactions, the distinction between lump-sum and per-unit rates, the effect of totals and averages, and the scope of the slip rule.

Disposition. The Court of Appeal allowed the appeals, save for the challenge concerning redaction of the corrected information in Annex 3.

1. Applicable test. There was one test, not separate old and new tests. The court applied the fact-sensitive approach in Scott v Scott [1913] AC 417 and R (Mohamed) v Secretary of State for Foreign and Commonwealth Affairs (No. 2) [2010] EWCA Civ 65. Open justice carries a strong presumption, but may yield where the interests of justice require it. Powerful reasons supported by cogent evidence directed to the specific information are required. Technical trade secrets will usually require protection, but classification as a trade secret under the Trade Secrets (Enforcement, etc) Regulations 2018 (SI 2018/597) does not automatically require redaction.
2. Financial information. The approach in Unwired Planet v Huawei [2017] EWHC 3083 (Pat) and InterDigital v Lenovo [2023] EWHC 1577 (Pat) remained applicable. No rational distinction existed between lump sums and per-unit figures, whether unpacked or taken from a licence. Rough or inaccurate reverse engineering could still harm negotiating positions, and the unpacked rates themselves had commercial value. Cogent evidence showed that publication would cause real commercial harm. The figures therefore had to be redacted.
3. Aggregates. Totals and averages also had to be redacted because their publication, particularly alongside disclosed individual entries, would enable reasonable approximations of redacted figures and undermine confidentiality.
4. Slip rule. Under CPR r40.12, an accidental slip or omission could be corrected at any time. A third party could raise the issue; agreement was not a prerequisite. The restrictions that an error be immaterial and that correction involve no rewriting were wrong. The rule could not be used for second thoughts, reconsideration or as a substitute for an appeal. The two errors identified were simple slips and required correction.
5. Remaining information. Specific evidence justified redaction of royalty rates, but no evidence specifically addressed the commercial significance of the sub-licensing provision. General assertions were insufficient. The corrected information about sub-licensing was therefore not to be redacted.

• Court of Appeal (Civil Division): In the present confidentiality appeal, the court allowed the appeals save for the issue concerning redaction of corrected Annex 3 information. The parties were invited to agree consequential arrangements.
• High Court of Justice, Patents Court: Marcus Smith J’s consequential judgment, [2024] EWHC 197 (Ch), ordered publication of a less-redacted version of the FRAND judgment. The underlying FRAND decision was [2023] EWHC 1095 (Ch); its substantive findings were addressed in a separate appeal, [2025] EWCA Civ 552.