International Patent Application Guide

International Patent Application Guide

How to File an International (PCT) Patent Application

This guide is for International (PCT) Patent Applications filed with the Intellectual Property Office of Singapore as a Receiving Office.

For “domestic” Singapore filings, please see our Singapore Patent Guide. If you’re looking to enter the Singapore National Stage of an International (PCT) Patent Application, please see our PCT Singapore National Phase Guide.

When you instruct us to file a PCT application with IPOS as the Receiving Office, please let us have the following:

1. Patent Specification

A full specification in English of the patent application, including description, claims, abstract and any drawings. Please let us have this in editable format (e.g., Microsoft Word). We can draft patent specifications in a variety of technologies on your instructions - please get in touch with us.

Please indicate which figure you wish the patent specification to be published with (e.g., Figure 1).

The patent description, claims, abstract and drawings should comply with the formal_requirements of the Patent Cooperation Treaty. Formal drawings are not required at the point of filing, but it is advisable to include them with the filing if at all possible. We can help prepare formal drawings if needed.

2. Priority Details

The country, date of filing and serial number of each earlier patent application from which priority is claimed. Please also let us have a certified copy of the priority document as soon as possible.

3. Applicant Details

For each applicant who is an individual (natural person): full name, address, country of residence and citizenship.

For each applicant which is a corporate bodiy (legal person): full name, registered address and country of incorporation.

Please note that at least one of the applicants must be a citizen or incorporated in Singapore, or be a resident of Singapore, in order for IPOS to act as a competent Receiving Office for the PCT application.

4. Inventor Details

Full name, address, country of permanent residence and citizenship for each inventor.

5. International Search Authority

Please let us know which International Searching Authority you wish us to nominate to search this application. The following International Searching Authorities are available for a PCT application filed with IPOS as Receiving Office:

Austrian Patent Office, Australian Patent Office, European Patent Office, Korean Intellectual Property and Japan Patent Office.


Please provide details of any biological deposits made under the Budapest Treaty and information as to whether prior disclosure at an international exhibition has taken place.

Power of Attorney

No Power of Attorney is needed for a PCT application filed with IPOS. However, we consider it good practice to have Powers of Attorney executed by each of the Applicants and Inventors and held on file, as they are needed in some circumstances during the prosecution of this case. We will provide Powers of Attorney after the application is filed for your execution.

Declaration of Inventorship

We consider it good practice to have a Declaration of Inventorship executed for the purposes of the US portion of the International Application. We will provide a Declaration of Inventorship after the application is filed for your execution.

Excess Claims Fees

There are no excess claims fees payable on filing a PCT patent application.

Prosecution Deadlines

Deadline for Filing Certified Copy of Priority Document

16 months from the earliest priority date claimed, or if no priority is claimed, 16 months from the date of filing.

Deadline for Filing Declaration of Inventorship

16 months from the earliest priority date claimed, or if no priority is claimed, 16 months from the date of filing.


The PCT application will be published by WIPO as soon as possible after 18 months from the earliest priority date (or the filing date, if no priority is claimed), usually the first Thursday following.

Deadline for Filing a Demand for Chapter II Processing

22 months from the earliest priority date claimed (if no priority is claimed, 22 months from the date of filing), or 3 months from the date of the Written Opinion of the International Search Authority (WO(ISA), whichever is later.

Deadline for Entering National Phase

An International application cannot mature to grant. The PCT application needs to be converted into separate national and regional applications by the national phase entry deadline, for processing before the various regional and national patent offices.

The national phase entry deadline is 30 or 31 months from the earliest priority date claimed, depending on the country concerned. If no priority is claimed, the deadline for entering the national phase is 30 or 31 months from the date of filing (again depending on the country concerned).

Annuities / Renewal Fees / Maintenance Fees

No renewal fees (maintenance fees or annuities) are payable on a PCT application.


If you have any questions on international patent protection, please get in touch with us.