Protecting a new idea by keeping it secret often seems like a good plan, but doing too good a job of keeping something secret is self-defeating. It keeps one from evaluating the idea.. Getting information on technology, costs, pricing, etc. is important and sometimes requires disclosing information about the invention. The risk inherent in that is often worth taking. After all, most ideas and inventions end up on the trash heap and getting good data, early on in the game, on the basic questions of  feasibility, cost and market acceptance is the best way to limit your losses.


Disclosures made in confidence (e.g., to a machinist you’re hiring to make a prototype) generally don’t ruin your chances of patenting the invention. By itself, this is a good reason to use non-disclosure agreements during the development process. .


On the other hand, most countries hold that publicly disclosing something in enough detail that the essential inventive bits and pieces are revealed makes it instantly non-patentable. There are exceptions. In particular, there are grace periods after a public disclosure during which the invention remains patentable in some countries.  A relative handful of countries provide grace periods for any sort of disclosure. Others allow for a period of public testing, for presentations at inventors’ exhibitions or technical society meetings. In addition, some countries allow for patenting after an abusive disclosure (i.e., those made by someone who was under a confidential disclosure agreement but who violated that agreement and disclosed the invention).


The following table, which may be grossly out of date as of this posting, lists grace periods during which a patent can be filed after an invention has been disclosed. The reader is cautioned to seek competent and timely advice before relying on any of these stated grace periods.



General grace period for any sort of public disclosure

Abusive disclosures by others  or display at international invention exhibition

Other special cases

Grace period for utility models


1 yr

No special provision

Testing in public may extend beyond 1 year in special cases

The US does not register utility models


1 yr





6 mo





6 mo




Europe – all states in EPO

NO general grace period

6 mo


The EPO does not register utility models, but many European countries do.


Same as EPO

Same as EPO

Testing in public for 6 mo.


Germany,  Austria, Czech Republic,


Same as EPO

Same as EPO


6 months general grace period for any type of disclosure..


Same as EPO

No set limit on abusive disclosures.

6 mo for disclosure at professional or technical society meetings



No general grace period

Similar to EPO.

Similar to Portugal



Source: http://www.ipr-helpdesk.org/documentos/docsPublicacion/html_xml/8_GracePeriodinventionLaw[0000004514_00].html



David A. Kiewit
Registered Patent Agent
5901 Third St. South
St. Petersburg FL 33705-5305
+1 (727) 656-0669 voice

+1 (760) 841-0989 fax
questions to: [email protected]
Copyright 2002-2009 by David A. Kiewit
All rights reserved



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