Costs and security for costs: costs drivers
Costs in a patent dispute are driven by scope, not by the size of the claim. The number of patents at issue, the number of forums involved, and whether validity is fought alongside infringement move the bill more than anything else. Security for costs is a separate, narrower question: whether the claimant must fund the defendant's exposure before the case proceeds. The two questions are linked but decided separately, and both are set early, not at the end.
How the mechanism works
Security for costs is a procedural safeguard, not a penalty. A party asks the forum to order the other side to lodge funds or a guarantee covering the costs it would face if it wins and cannot recover them afterwards. The application is usually made against a claimant with limited assets in the relevant jurisdiction, or with an asset base that is hard to reach after judgment. The decision-maker weighs the applicant's grounds against the risk of shutting out a legitimate claim through cost pressure alone.
Cost drivers work on a similar logic. Nothing in the mechanism fixes an amount in advance. Instead, the forum and the parties build the estimate from a defined set of variables: how many patents and claims are contested, how many jurisdictions run in parallel, whether experts are needed, and how much translation and evidence preparation the record requires.
| Cost driver | Why it moves the estimate |
|---|---|
| Number of patents and claims in dispute | Each additional patent adds its own technical analysis and evidence set |
| Number of parallel forums | Filings, translations and local counsel multiply per forum |
| Validity contested alongside infringement | Doubles the evidentiary track and often requires separate experts |
| Technical complexity of the invention | Longer expert reports and longer hearings |
| Security for costs application | Adds an interim procedural stage before the substantive case starts |
What changes for your timeline and risk
Once a security for costs application is filed, the substantive timetable usually pauses until it is resolved. This is the point of no return in practical terms: if the ordered security is not lodged within the set deadline, the claim can be struck out without a hearing on the merits. Missing that deadline is rarely reversible, so it needs treating as a hard date, not a target.
If the underlying dispute traces back to work commissioned inside a group — for instance where When a subsidiary paid for work the parent uses is the live question — cost allocation between the related entities is a separate exercise from security for costs, and confusing the two usually delays both.
What to do
- List every patent, claim and forum in play before estimating cost exposure — the client or its counsel maps this first.
- Check the other side's domicile and asset base early; this determines whether a security for costs application has grounds.
- File the application, if grounds exist, at the earliest procedural window the forum allows — late applications are routinely refused on timing alone.
- Prepare a cost estimate with supporting invoices or rate schedules to back the figure requested.
- Calendar the response and payment deadlines the moment an order is issued; treat them as fixed.
- If the application is refused, assess whether the forum's rules allow an interim appeal before the substantive case resumes.
Who decides and how long it takes
The panel or judge assigned to the case decides the application, usually at the case management stage rather than at trial. There is no fixed statutory clock here that applies across forums; the timetable is set by the deciding body once it has the application and any response in hand. That is why the calendar for the application matters more than a general estimate of duration.
Enforcement of a costs order, once made, follows the same logic decision-makers apply elsewhere in registered-rights disputes: title and standing are checked before relief is granted. The reasoning is set out in detail in Enforcement against a holder step by step in detail, which covers a different asset class but the same enforcement logic.
Different scenarios
If the claimant is based inside the EU with a visible asset base, a security for costs application rarely succeeds and is often not worth filing. If the claimant is based outside the EU or operates through a thinly capitalised vehicle, the application has a stronger footing and should be filed as early as the rules allow. If validity is contested in parallel with infringement, budget for the application stage to run longer, since the forum typically wants to see the shape of the full dispute before ruling on security.
What this page does not cover
This page sets out the mechanism and the stages. It does not set an amount, since no forum publishes a fixed tariff for security for costs — the figure is built case by case from the drivers above. It also does not cover the underlying infringement or validity merits, only the procedural cost layer around them. Where the other side is based outside the EU, checking its standing and assets before filing narrows the application considerably; see how that check is built in Counterparty in United Arab Emirates in practice.
Verified
Reviewed: October 2025. The procedure above reflects how security for costs applications and cost-driver assessments are generally run across patent forums; forum-specific timetables are checked separately for each matter. Our approach to collecting and dating sources is set out in Methodology: collection, cross-checking and dating and its limits.
FAQ
How long does costs and security for costs take in practice?
There is no fixed duration. The timetable is set by the deciding body once the application and any response are filed, and it depends on how many drivers — patents, forums, experts — are already in play.
Which documents are needed to start?
A cost estimate with supporting rate schedules or invoices, a summary of the drivers involved, and evidence of the other side's domicile or asset position where security is sought.
What happens if the other side does not respond?
Most forums allow the application to proceed on the papers filed, and silence does not block a ruling. A missed deadline afterwards, however, can still lead to the claim being struck out if security was ordered and not paid.
Related publications
If validity is the live issue rather than costs alone, Stay pending validity step by step sets out how that stage is run and where it interacts with cost exposure.
If your situation is different
Where the dispute started because a joint development partner filed alone, the cost drivers above still apply, but the starting point is different — see A joint development partner files alone patent.
Where the dispute is about licence income rather than the patent itself, the cost logic shifts toward accounting evidence rather than technical experts — covered in When royalties are underreported in practice.
Where the underlying friction is a blocked audit right rather than an open dispute, the drivers and the forum both change — see When an audit clause is refused in detail.
Vaidas Kudirka
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