Why grace periods matter
To be patentable, an invention must be new at its priority date. In most countries, anything made public before that date counts against you, including your own product launch, website, conference paper or pitch to investors without a confidentiality agreement. A grace period carves out an exception: for a limited time, your own disclosure is disregarded when your application is examined.
Grace periods are a safety net, not a strategy. They protect against your own disclosure, but not against what other people do in the meantime. If a competitor independently publishes or files for the same invention after your disclosure but before your application, the grace period generally won't help you against that.
Australia
Australia has a 12-month grace period for information made public by the inventor or applicant, or with their consent. To rely on it, a complete application, which can be a PCT application designating Australia, must be filed within 12 months of the disclosure. Filing a provisional application within that time is not enough on its own. No declaration is needed when you file, and the grace period is applied if the disclosure is raised during examination.
United States
The United States allows 12 months for disclosures by the inventor, or by others who obtained the information from the inventor. Unusually, the 12 months is counted back from the effective filing date, which includes a valid priority date. A provisional filed within 12 months of the disclosure can therefore preserve your position in the US, provided it properly discloses what you later claim.
Europe
The European Patent Convention has no general grace period. Article 55 disregards a disclosure only in two narrow cases, both within six months before filing: an evident abuse against the applicant, such as a breach of confidence, and display at an officially recognised international exhibition, of which there are very few. A product launch, a paper or a crowdfunding page before filing will generally destroy novelty for a European patent. Most European national patent laws follow the same approach.
China
China allows six months, but only in limited circumstances: first display at an international exhibition sponsored or recognised by the Chinese government, first disclosure at a prescribed academic or technical meeting, disclosure by someone else without the applicant's consent, and, since 2021, first disclosure in the public interest during a national emergency. Ordinary commercial disclosure is not covered, and some of these exceptions must be claimed when the application is filed. In practice, China should be treated as having no grace period for commercial disclosures.
Japan
Japan has allowed 12 months since 2018. The disclosure must be by the person entitled to the patent or result from their actions, and you must claim the grace period formally: a declaration at filing, followed by supporting evidence within 30 days. The 12 months is measured to the actual filing date in Japan, or the international filing date of a PCT application, not to an earlier priority date.
South Korea
Korea also allows 12 months for the applicant's own disclosures, measured to the actual Korean or PCT international filing date. A formal claim to the grace period is required, and it is generally best made when the application is filed.
Canada
Canada disregards disclosures made by the applicant, or by someone who obtained the information from them, within 12 months before the Canadian filing date. For a PCT national phase application that is the international filing date. As in Japan and Korea, an earlier priority date doesn't extend the 12 months.
New Zealand
New Zealand introduced a general 12-month grace period at the end of 2018 for disclosures made by the patentee, by someone deriving title from them, or with their consent. As in Australia, a complete application must be filed within 12 months of the disclosure, and a provisional alone does not satisfy the requirement.
India
India's grace period is limited to specific situations, such as display at certain exhibitions, papers read before learned societies and reasonable trials of the invention, with an application filed within 12 months. There is no general grace period for commercial disclosure.
The trap in "disclose first, then file a provisional"
Several of these grace periods are measured to the filing date of the complete or PCT application, not the date of a provisional. That catches people out.
Suppose you launch a product, file a provisional four months later, and then file a PCT application at the usual 12-month mark. The PCT application is filed 16 months after your launch. In Australia, New Zealand, Japan, Korea and Canada, that is outside the grace period, even though the provisional was filed well within 12 months. Only the United States, which counts back from the priority date, would forgive the launch. If you have already disclosed, the complete or PCT application may need to be filed within 12 months of the disclosure, which can mean skipping or shortening the provisional stage.
A grace period forgives your own disclosure in some countries, on some conditions. Filing before you disclose works everywhere.
What this means in practice
The safest course is still to file a properly prepared provisional before any public disclosure. Once a provisional that fully discloses the invention is on file, you can launch, publish and pitch with confidence, because your claims rely on a date before any of that happened. That only works if the provisional genuinely supports what you later claim. If it doesn't, the claims fall back to a later date and your own launch can become prior art in the countries without a grace period, as we explain in the pitfalls of a poorly prepared provisional patent application.
If you have already disclosed your invention, don't assume it is too late, but don't wait either. The deadlines run from the disclosure, and the right filing strategy depends on which countries matter to you. Contact Patentec for a free initial consultation and we'll work out what can still be protected and where.