A granted Singapore patent carries a presumption of validity, but that presumption is not permanent. Competitors, alleged infringers and other interested parties can challenge a patent’s validity and have it struck off the register entirely through a revocation application. For a company that has built a product around a competitor’s shaky patent, or that has been threatened with infringement proceedings over a patent it believes should never have been granted, revocation is often the most direct way to clear the field.
This article explains how a patent revocation application works in Singapore: the legal basis, who can bring one, the step-by-step process before the Registrar of Patents, the documents and costs involved, and what happens once a patent is revoked.
What a Patent Revocation Application Is
Patent revocation is the formal legal process for cancelling a granted Singapore patent on the basis that it should never have been granted, or should not have been granted in its current form. Unlike an opposition, which happens before a patent is granted, revocation targets a patent that is already on the register and already enforceable.
If successful, the patent is removed from the register, or the relevant claims are struck out, as if the patent (or the affected claims) had never existed. This matters commercially because a company accused of infringing a patent it considers invalid has a powerful defence: if the patent should not have been granted, there is nothing to infringe.
Revocation is distinct from a court application to restrain groundless threats of infringement, which deals with improper threats rather than the underlying validity of the patent itself. It is also distinct from an opposition to a patent application, which must be filed before grant. Revocation is the only route once the patent has already been granted and entered on the register.
Legal Basis: Patents Act 1994, Sections 80 and 82
The grounds for revoking a Singapore patent are set out exhaustively in section 80 of the Patents Act 1994. A patent may be revoked on any of the following grounds:
- The invention is not a patentable invention, that is, it lacks novelty, does not involve an inventive step, is not capable of industrial application, or falls within an excluded category;
- The patent was granted to a person who was not entitled to be granted that patent;
- The specification of the patent does not disclose the invention clearly and completely enough for it to be performed by a person skilled in the relevant field;
- The matter disclosed in the specification extends beyond what was disclosed in the application as filed;
- An amendment or correction that should not have been allowed was made to the specification or the application;
- The patent was obtained fraudulently, by misrepresentation, or by non-disclosure or inaccurate disclosure of prescribed material information; or
- The patent is one of two or more patents granted for the same invention with the same priority date, filed by the same party or its successor in title.
In practice, the three grounds most commonly relied on are lack of novelty, obviousness (no inventive step) and insufficiency of disclosure.
Jurisdiction is the part of this area most often misunderstood, and the Court of Appeal addressed it directly in Sunseap Group Pte Ltd and others v Sun Electric Pte Ltd [2019] SGCA 4. The court drew a clear line between two categories of case. Where a patent owner sues for infringement in the General Division of the High Court, a defendant may counterclaim for revocation of the specific claims alleged to be infringed, as validity can be raised by way of defence under section 82 of the Patents Act. But where a party wants to revoke a patent independently, without an existing infringement action, section 82 makes clear that validity can only be put in issue in proceedings before the Registrar of Patents under section 80. The High Court does not have original jurisdiction to hear a standalone revocation application; that jurisdiction belongs exclusively to the Registrar at the Intellectual Property Office of Singapore (IPOS). A decision of the Registrar can subsequently be appealed to the High Court.
For most companies considering revocation, this means the application is filed with IPOS, not the courts, unless the patent owner has already commenced an infringement suit.
Who Can Apply
An application for revocation under section 80 may be brought by any interested party, which in practice includes:
- A company accused of, or concerned about, infringing the patent;
- A competitor whose product or business is restricted by the patent’s existence;
- A licensee or former licensee with an interest in challenging the scope or validity of what it has licensed; or
- Any other person with a genuine commercial interest in having the patent removed or narrowed.
Where revocation is sought as a counterclaim in the course of an infringement action already on foot in the General Division of the High Court, it is the defendant to that action who brings the counterclaim, and only in respect of the claims actually asserted against it.
Step-by-Step Process
1. Filing the Application
The applicant files an Application for Revocation of Patent with the Intellectual Property Office of Singapore (IPOS), together with a statement setting out the grounds of revocation in detail, the facts relied upon, and the relief sought. A prescribed fee is payable on filing, and copies of the application and statement must be served on the patent proprietor.
2. Proprietor’s Counter-Statement
The patent proprietor has three months from receipt to file a Counter-Statement if it intends to contest the application. The proprietor may also propose amendments to the patent specification at this stage, for example to narrow a claim to avoid prior art.
3. Notification to Registrar and Choice of Forum
After the counter-statement is filed, both parties receive a Notification to Registrar form, to be completed within one month. This includes the option to request mediation or expert determination instead of litigation before the Registrar. If both sides agree, the proceedings may be suspended while an alternative route is tried.
4. Exchange of Evidence
If the matter proceeds to litigation, the applicant files a statutory declaration (the Evidence by Initiator) setting out the evidence supporting its grounds of revocation, typically within three months of the counter-statement. The proprietor then files its own evidence in response, followed by a reply from the applicant if needed.
5. Case Management Conference
The Registrar convenes a case management conference to give directions, including, in appropriate cases, a direction for the applicant to request re-examination of the patent. Directions on any proposed amendment to the specification and the hearing date are also fixed here.
6. Hearing and Decision
Parties file written submissions and bundles of authorities in advance, and the Registrar hears the matter and issues a decision with reasons.
7. Appeal
A party dissatisfied with the Registrar’s decision may appeal to the General Division of the High Court within six weeks of the decision date.
Documents Required
| Document | Purpose |
|---|---|
| Application for Revocation of Patent form | Commences the proceedings before IPOS |
| Statement of grounds of revocation | Sets out the section 80 grounds relied on and the relief sought |
| Prior art and supporting evidence | Documents, publications or prior patents establishing lack of novelty or obviousness |
| Proprietor’s Counter-Statement | Proprietor’s response contesting the application |
| Statutory declarations (Evidence by Initiator and Respondent) | Formal evidence substantiating each party’s position |
| Notification to Registrar form | Confirms choice between mediation, expert determination or litigation |
| Written submissions and bundle of authorities | Filed ahead of the hearing to support oral argument |
Timeline and Costs
| Stage | Typical Timeframe | Indicative Cost |
|---|---|---|
| Filing application and statement | Day 0 | Prescribed IPOS filing fee (a few hundred Singapore dollars) |
| Counter-statement | Within 3 months of service | Legal fees for drafting and filing |
| Evidence exchange (both sides, including reply) | Roughly 6 to 9 months, depending on extensions | Significant, driven by expert and technical evidence |
| Case management conference and re-examination (if directed) | Several months, overlapping with evidence stage | Separate re-examination fee if directed |
| Hearing and decision | Typically 12 to 24 months from filing, for a contested matter | Hearing and submission costs, often the largest component |
| Appeal to the High Court (if pursued) | Within 6 weeks of the Registrar’s decision | High Court litigation costs |
Overall cost depends heavily on how technically contested the patent is, the volume of prior art evidence, and whether experts are engaged. Straightforward matters resolved through mediation or expert determination are considerably cheaper and faster than a fully litigated hearing with an appeal.
What Happens After the Order
If the Registrar revokes the patent, it is removed from the register, or the specific claims found invalid are struck out, with effect generally treated as if those rights never existed. This has immediate commercial consequences: any pending or threatened infringement action based on the revoked claims falls away, licensees may be entitled to stop paying royalties on the revoked scope, and competitors are free to operate in the space the patent previously blocked.
Where only some claims are revoked and others survive, the patent continues in its narrowed form, and the proprietor must file a clean copy of the amended specification. Costs of the hearing are usually awarded to the successful party, assessed under the Patents Rules if the parties cannot agree a sum between themselves.
For a company that successfully defends its freedom to operate, it is sensible to document the outcome clearly in board minutes and, where relevant, update any licensing or supply agreements that referenced the now-revoked patent. Companies should also review how the patent was recorded for writing-down allowance purposes if it was previously treated as a tax-deductible IP asset.
Frequently Asked Questions
Can I apply to the High Court directly to revoke a patent?
Only if there is already an infringement action in the General Division of the High Court, in which case revocation may be raised as a counterclaim limited to the claims actually asserted against you. A standalone revocation application, where no infringement suit exists, must be brought before the Registrar of Patents at IPOS under section 80 of the Patents Act.
What is the most common ground for revocation?
Lack of novelty and obviousness (absence of an inventive step) are the grounds most frequently relied on, usually supported by prior art such as earlier patents, publications or product disclosures that predate the patent’s priority date.
How long does a contested revocation take?
A fully contested matter that proceeds through evidence exchange to a hearing commonly takes 12 to 24 months from filing, longer if an appeal to the High Court follows.
Can the parties settle instead of going to a hearing?
Yes. The Notification to Registrar process specifically offers mediation or expert determination as alternatives, and many revocation disputes settle once the patent proprietor sees the strength of the prior art evidence.
What happens to my product if the patent blocking it is revoked?
Once the relevant claims are struck off the register, there is no longer a valid patent right to infringe in respect of those claims, and any related infringement proceedings based on them cannot succeed. You should still take legal advice before resuming or expanding activity, particularly if an appeal is pending.
Do I need a patent agent as well as a lawyer?
Most companies engage both a Singapore Advocate and Solicitor experienced in patent litigation and a registered patent agent for the technical drafting and prior art search, given the overlap between legal argument and technical subject matter in these proceedings. This sits alongside other IP protections your company may already rely on, such as patent registration with IPOS, trademark registration with IPOS, and common law protections like passing off and Anton Piller orders in appropriate cases. Background reading on patent litigation forums is also available via JustFollowLaw.
Need Help With This Matter?
If your company is facing this situation, Raffles Corporate Services can assist with the groundwork, ACRA filings, compliance documentation, and coordinating with experienced Singapore law firms. For matters requiring court proceedings, we work with a panel of experienced Singapore law firms who offer cost-effective and efficient legal service and advice.
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This article is for general information only and does not constitute legal advice. For advice specific to your situation, please consult a qualified Singapore Advocate and Solicitor.
The Editorial Team, Raffles Corporate Services