Revoking a Granted Patent
Learn about the process to revoke a granted patent in Singapore, including forms, fees, deadlines, steps, mediation and expert determination options.
Last updated 23 October 2025
If you are facing the prospect of (or are currently involved in) a dispute and do not have legal representation, we strongly recommend that you seek legal assistance.
Sections 80 - 84 of the Patents Act
Rules 80 - 85 and 5 - 7 of the Patents Rules
1. A person may apply to revoke a granted patent by filing an application for revocation. The procedure is as follows:
File with us Form PF35 and a statement of grounds that includes the facts upon which the applicant relies and the relief which he seeks (together with payment of S$500).
Send to the proprietor a copy of the same Form PF35 and statement at the same time that they are filed with us.
2. Within 3 months from the date of receipt of the application for revocation from the applicant, if the proprietor wishes to contest the application, he must file a counter-statement in Form HC6 that includes the grounds on which the application is contested. The procedure is as follows:
File with us Form HC6 (together with payment of S$360).
Send to the applicant a copy of the same Form HC6 at the same time that it is filed with us.
If these steps are not complied with, the proprietor will not be allowed to take part in the subsequent proceedings. We will consider the application for revocation as if each specific fact set out in the statement were conceded, except in cases where it is contradicted by a document in our possession.
At any point during the proceeding, a party may request for an extension of time under Patents Rule 108A. The procedure is as follows:
Send a notice to the other party, and every other person likely to be affected by the extension stating the intention to request for an extension of time, particulars of the extension, and reason for the extension. In the same notice, request that the other party or person give his written consent to the extension within 2 weeks after the date on which the notice is served on him.
File with us Form HC3 (together with payment of S$130, if it is not the first request). Attach a copy of the notice sent to the other party or person and written consent, if given.
2a. When the proprietor files a counter-statement, he may at the same time file an amendment of the specification by submitting the proposed amendment together with Form HC6. Send to the applicant a copy of the amendment at the same time that it is filed with us.
2b. The proposed amendment will be advertised in the Patents Journal. A person may obtain further details of the patent by filing Form CM10 (together with payment of S$30).
2c. Within 2 months from the date of advertisement, a person may oppose the proposed amendment by filing a notice of opposition in Form PF58. The procedure is as follows:
File with us Form PF58 and a statement that includes the facts upon which the opponent relies and the relief which he seeks (together with payment of S$480).
Send to the proprietor a copy of the same Form PF58 and statement at the same time that they are filed with us.
3. The revocation proceedings are suspended from the date that the counter-statement is filed. Parties will be encouraged to engage each other to explore dispute resolution options. Parties will receive the following documents:
A Notification to Registrar form to be completed by each party and returned to us, copying the other party, within 1 month. The form includes a Request for WIPO Mediation form and an Agreement and Request for WIPO Expert Determination in IPOS Patent Proceedings form, for parties' use if they wish to submit to mediation or expert determination by the WIPO Arbitration and Mediation Center.
An infosheet and Frequently Asked Questions on the Revised Enhanced Mediation Promotion Scheme by IPOS.
Click here to learn more about the mediation option for IPOS proceedings and the available funding under the Revised Enhanced Mediation Promotion Scheme. Click here to learn more about the expert determination option for IPOS patent proceedings. Once parties let us know of their intention to request for mediation or expert determination, we will generally suspend the IPOS proceedings for the mediation or expert determination to take its course.
Notwithstanding the specific incorporation of the mediation and expert determination options to the procedure after the counter-statement is filed, parties may request for mediation or expert determination at any time before we decide on the outcome of the case.
If parties do not wish to request for mediation or expert determination at this point in time, we will resume conduct of the proceedings. We will specify deadlines for the filing of evidence and raise any issues with the application for revocation and counter-statement, in writing or in a Case Management Conference.
4. The applicant may file a statutory declaration setting out the evidence he wishes to adduce in support of his case. The procedure is as follows:
Within 3 months from the date of issuance of evidential timelines, file with us a statutory declaration in the Evidence by Initiator Form.
Send to the proprietor a copy of the same statutory declaration at the same time that it is filed with us.
If these steps are not complied with, the applicant is deemed to have abandoned his application.
5. Optionally, after receipt of the applicant’s statutory declaration, the proprietor may file a statutory declaration setting out the evidence he wishes to adduce in support of his case. The procedure is as follows:
Within 3 months from the date of receipt of the applicant’s statutory declaration, file with us a statutory declaration in the Evidence by Respondent Form.
Send to the applicant a copy of the same statutory declaration at the same time that it is filed with us.
6. Optionally, after receipt of the proprietor’s statutory declaration, the applicant may file a statutory declaration setting out further evidence confined to matters strictly in reply to the proprietor’s statutory declaration. The procedure is as follows:
Within 3 months from the date of receipt of the proprietor’s statutory declaration, file with us a statutory declaration in the Evidence in reply by Initiator Form.
Send to the proprietor a copy of the same statutory declaration at the same time that it is filed with us.
After this stage no further evidence may be filed unless we specifically allow.
7. At any time after the completion of the filing of evidence by the parties, we will direct the parties to attend a case management conference. We may consider any matter including re-examination and amendment of the specification.
8. The applicant for revocation may be directed to request for re-examination, within 2 months from the date of our direction. The procedure is as follows:
File with us Form PF36 (together with payment of S$900 and any additional items that we specify e.g. security for costs).
If these steps are not complied with, the applicant shall be deemed to have abandoned his application.
The re-examination will take into account the representations of both parties, as well as any amendment of the specification. We will provide the re-examination report to both parties.
9. We will direct the parties to attend a case management conference to discuss the conduct of the case in light of the re-examination report, as well as to give directions relating to the amendment of specification, if any. If the proposed amendment is allowed, the proprietor shall file a clean copy of the amended specification within 1 month from the date of our direction.
10. We will notify the parties of a date on which we will hear arguments on the case. The parties shall file with us their written submissions and bundles of authorities in the Written Submissions & Bundle of Authorities Form at least 1 month before the date of hearing and shall at the same time exchange with one another their respective written submissions and bundles of authorities. Any party who intends to appear at the hearing shall file with us Form HC1 (together with payment of S$1,000) before the hearing.
11. After the hearing, we will inform the parties of our grounds of decision.
12. The parties can appeal our decision within 6 weeks after the date of our decision. An appeal should be filed at the General Division of the High Court. The appellant shall serve a copy of the notice of appeal on us and on the respondent within 7 days after filing the notice of appeal.
13. After we issue a decision, costs will usually be awarded to the winning party. The parties should try to agree on the sum for these costs between themselves. If the parties cannot agree on the sum to be paid to the winning party, the winning party can apply for a taxation hearing. This is done by filing with us a bill of costs in the Bill of Cost Form within 8 weeks from the date of our decision. Send to the other party a copy of the same bill of costs at the same time that it is filed with us.
The paying party can object to any of the itemised costs by marking the bill of costs with “Agree” or “Disagree” against each itemised cost. This is done by filing with us the Marked Bill of Cost Form within 1 month after receipt of the bill of costs. Send to the other party a copy of the same marked bill of costs at the same time that it is filed with us.
The matter will be fixed for an assessment of costs. We will award costs according to the Scale of Costs in the Third Schedule of the Patents Rules, which sets out the range of costs a party may be awarded for each particularised item. It should be noted that the costs awarded are not intended to compensate parties for their expense. We will make the Registrar's certificate for the amount of the assessed costs.