UKIPO Tightens the Space for “Zombie” Marks and Bad-Faith Stockpiling While PTAB Narrows Serial Petitions

The UK conversation around bad-faith stockpiling and “zombie” marks is not just a passing enforcement headline. The verifiable public materials point to a broader tightening. After SkyKick, UKIPO told examiners to look actively at specifications that are manifestly and self-evidently broad, and from 1 April 2026 the forms and fees for revocation and invalidation have also been updated. The practical message is that the UK system is becoming less tolerant of filings built to occupy space first and justify business use later.

Across the Atlantic, the PTAB story should also be framed carefully. The current signal is not that a brand-new serial-petition final rule has already taken effect. The stronger point is that, since March 2025, the Director’s interim discretionary process has pushed serial petitions, parallel petitions and related issues into a dedicated institution-stage filter, and later guidance on prior findings has made repeat attacks on the same patent even harder to treat as routine. Different tools, same instinct: procedure is being pulled back toward bona fide dispute resolution rather than procedural warehousing or attrition.

1. This is not simply about being “stricter”; it is about redefining what the system is willing to process

On both sides of the Atlantic, the more interesting development is not a generic rise in scrutiny. It is a narrowing of institutional patience for procedural behaviour that looks strategically clever on paper but commercially thin in substance. In trade marks, that means filings drafted to occupy a wide field without a correspondingly real plan for use. In patent disputes, it means repeated or re-packaged challenges that can turn process itself into leverage.

That distinction matters. Intellectual property systems are not designed to reward procedural inventory for its own sake. They are supposed to support genuine branding, genuine technical disputes and enforceable rights with identifiable commercial content. Once offices and tribunals begin acting on that premise more openly, the market should not read the change as an isolated tweak. It is a signal that “technically fileable” no longer means “institutionally welcome” in the same way it once did.

2. In the UK, the real pressure point is the file-broad-now, explain-later model

The most important UK shift is not a slogan. It is the way bad-faith analysis has been moved closer to the front end. UKIPO’s post-SkyKick guidance makes clear that examiners should consider whether a specification is manifestly and self-evidently broad, and whether that breadth raises a bad-faith issue. That matters because pressure on overbroad filings does not have to wait for opposition, revocation or invalidation. The application stage itself can now become a more active filter.

At the same time, the 1 April 2026 changes to forms and fees make the back-end route more structured. For genuine rights holders, that does not automatically mean proof burdens have become easy. It does mean that revocation and invalidation pathways are easier to budget for, easier to timetable and easier to integrate into a coherent enforcement plan. For applicants that have relied on very wide lists with little real preparation for use, that is a material change. They may now need to justify the breadth earlier and face a clearer downstream threat if the filing is later challenged.

There is also a cost-discipline angle that should not be overlooked. UK trade mark proceedings are not based on full compensation, but the tribunal still retains room to move away from the ordinary scale where conduct becomes unreasonable. So even without a dramatic official slogan about “zombie marks,” the system is converting criticism of speculative filing behaviour into more concrete examination risk, revocation risk and cost risk.

3. PTAB is not tightening through a new final serial-petition rule; it is tightening through a gatekeeping sequence

The PTAB side needs careful wording. It is common in market commentary to say that the Board has “implemented new serial-petition rules.” The official picture is narrower and more procedural than that. The 2024 proposed rulemaking that addressed serial petitions and related issues was later withdrawn. What is actually operating is the March 2025 Director discretionary process, which pulls serial petitions, parallel petitions, parallel proceedings and Section 325(d) issues into a dedicated discretionary screen before the case moves fully into the merits phase.

That procedural sequencing changes a great deal. The question is no longer only whether the petitioner has found a slightly different reference combination or a more polished framing. The earlier question is whether another round of proceedings against the same patent is institutionally justified at all. If that answer is weak, the petition may face trouble before the substantive contest is even allowed to unfold. That makes repeated IPR activity more expensive to narrate and more difficult to normalize.

The later memorandum on prior findings reinforces the same direction. When core issues or challenged claims have already been considered elsewhere, PTAB is no longer signalling comfort with the idea that a repeat challenge is just another neutral filing event. This does not eliminate repeat attacks. It does, however, reduce their presumptive normality. Petitioners now need a cleaner explanation for why the next round deserves to exist.

4. What businesses should do now: stop relying on procedural inventory on both the trade mark and patent sides

For brand owners, the least efficient strategy now is to keep treating trade mark applications as a cheap storage device. The broader the specification and the thinner the real use preparation, the greater the exposure later at examination, revocation, invalidation or costs stage. The better approach is more disciplined and less theatrical: define the core goods and services more precisely, organise use evidence early, and review older registrations that remain on the books despite weak or fading commercial support.

For patent owners, accused parties and petitioners, the PTAB developments make early procedure mapping more important. Petitioners can no longer assume that a failed first attempt will be followed by a routine second pass with a different angle. Patent owners, meanwhile, should not confine their effort to merits responses alone. They should be ready to tell a joined-up story about serial petitions, parallel petitions, prior findings and procedural burden across district court, ITC and PTAB timelines.

Put together, the UK and US signals point in the same direction. Both systems are becoming less willing to subsidize procedural stockpiling and repeat pressure tactics. Rights built around real use and disputes grounded in a real need for adjudication will still find room. Strategies built around occupying space first, or filing one more round to see what sticks, are likely to face a colder reception than before.