Everything about priority

What is priority? 

Priority is a very important definition for applicants. It safeguard inventors’ interests by providing them with highly valuable rights; most importantly with time. If you will only remember one thing about priority, it should be the following: you have 12 months to file any patent applications for the same invention. This period of 12 months is often referred to as "priority year". The priority year is counted from the first filing, irrespective of whether the first filing was a European patent application or a national one (or even a utility model application).*

According to the priority right, anyone who files a patent application has the right to file a subsequent application for the same invention in another country – that is a member of the Paris Convention – within 12 months, without being exposed to the risk that their own first application will be cited as novelty-destroying in subsequent application procedures before other patent offices.**

The main effect of priority right is that when the novelty and inventiveness of the subsequent application is examined, the earliest date (filing date of the first application) will be considered as the effective date for determining the state of the art.

Let's see an example: You filed a patent application in Denmark on February 1, 2020. You received the first evaluation of patentability in September, and based on the report you decide to file a European patent application for the same invention. You can file the European patent application by February 1, 2021. If you validly claim priority, your Danish national application and any patent documents published after you filed your Danish national patent application will not be cited by the European Patent Office and cannot take away the novelty of your invention. The effective date of your European patent application will be February 1, 2020, as if it was filed then (and not one year later).

What are the advantages of claiming priority?

As you can conclude from the above, claiming priority has multiple beneficial effects. Let’s see more advantages.

1. Safety

   The filing date of your first application counts as the effective date for any of your subsequent applications. The effective date is the date by which the state of the art is assessed against your application. This means that you are safe against any documents published after the first filing date, as these will not be cited against you (unless exceptional circumstances occur).

2. Gaining certainty of the patentability of your invention

   Applicants have the possibility to evaluate the patentability of their invention in the priority year. The patent office where the first application is filed (for a lower cost than the European patent application), might send its first search report and evaluation in a few months. (A few offices work quite fast, for example Denmark.) Receiving the first opinion on patentability at early stage can help assess the chances of grant. If the first evaluation is rather positive, there is no question whether to file a European Patent Application in the priority year.

   However, please do remember that one patent office granting your patent does not guarantee that another will issue a grant too.

3. Time for commercial evaluation

   Applicants have time (12 months) to evaluate the commercial potential of their invention. Use this year to identify market opportunities and continue the development of your invention.

4. Win a year to decide where to file next

   If you use the priority year for identifying your market opportunities (see the point above) and start business negotiations, you will surely see some results, which can then help you decide in which countries subsequent patent applications for the same invention should be filed.

5. Saving money

   Applicants can spread out payments: applicants can postpone spending money on foreign patent application procedures – e.g. the quite costly European patent – until they have received a first report on the patentability of their invention. Filing one national patent application is not that expensive. After that, you have one year to plan your budget and decide about the future patent applications.

   You can claim priority of an application if the application has a valid filing date. A filing date will be accorded if certain requirements are satisfied. Paying the filing and search fees is not among these requirements (according to most patent systems), so your priority will be valid even if you have not paid any fees when filing your first application. This way, you can save even more money. We only suggest doing this if your budget is really tight, and you only need this first application for obtaining a priority right. In this case, the first application will have no other purpose, and also, it will be deemed withdrawn, since no fees have been paid.

6. Start the business

   Applicants can make their invention public (e.g. attend conferences, start crowdfunding campaigns, start business negotiations, marketing) without generating novelty-destroying prior art regarding any subsequent patent application(s) within twelve months.

7. Be the first, be safe

   For a certain state, the applicant who first filed will own the patent. If your priority date is earlier than someone else's filing date, you will be the one obtaining the patent.
   Thus, you can maintain the novelty of your invention for subsequent patent applications filed elsewhere within the priority year – even if someone else applied for a patent for the same or a similar invention in the meantime.

   Let's see an example. You have a patent application pending in Germany from the filing date of May 15, 2019. You then file a European patent application in December of 2019, claiming the priority of your German application. However, Company X also files a European patent application for the same invention, and they do it earlier than you: on June 1, 2019. In this case, you will get the European patent (of course, if you satisfy all the requirements, the priority is validly claimed, etc.), since your effective date (a.k.a the priority date, May 15) is earlier than Company X’s filing date (June 1).
   /You would obtain the patent and not Company X even if you filed the European patent application on May 15, 2020, because you are still in the priority year./

As a result, you should claim priority if you are an applicant that

• would like to have a first search report and search opinion within the priority year in order to decide whether to also file in other countries, and/or

• needs to raise more money to be able to continue the process.

What are the requirements?

In order to validly claim priority and enjoy the rights, applicants must fulfil certain conditions.

The subsequent patent application must be filed:

• by the same applicant
  (Or their successor in title - if the transfer has taken place before the filing of the application.)

• within 12 months from the first application
  (The previous application may be for a patent or for the registration of a utility model or for a utility certificate.)

• for the same invention

There are some further formal requirements (e.g. filing a copy of the previous application), but your patent attorney will take care of those.

When not to claim priority

It is very important to remember that the patent protection starts from the filing date and not from the earlier priority date. Therefore, you need to file the patent application as soon as possible if you would like to commercially exploit your invention, license the patent, sue for infringement, etc. 

Let's see an example with dates
Priority date: December 10, 2019 - US provisional application
Filing date: November 30, 2020 - German patent application

In this example, you have protection in Germany from November 30, 2020 (if your patent is granted later). For assessing novelty and inventive step, December 10, 2019 is the effective date. (Similar prior art documents published after December 10, 2019 will not be cited against your invention.) Also, if someone else files a patent application in Germany for the same invention in February, 2020, the patent will belong to you. (This is the "first-to-file rule".) This is what priority right is good for.
However, your exclusive right for Germany (for maximum 20 years) only starts on November 30, 2020. Consequently, you cannot sue someone for patent infringement that happened in Germany before November 30, 2020, because you did not have any patent rights in Germany during that period.

Whether priority should be claimed or not, and if the full priority year should be used or just a few months, will depend on your IP strategy and business plan. We suggest discussing this question with your patent attorney.

* This is described in Art. 87 EPC:
"Any person who has duly filed ... an application for a patent ... shall enjoy for the purpose of filing a European patent application in respect of the same invention a right of priority during a period of twelve months from the date of filing of the first application."
See the full legal text here.

** Paris Convention also covers other IP rights, such as trademarks. Consequently, applicants can claim priority for trademarks as well, but the term is shorter, maximum 6 months. However, priority rights of different IP rights cannot be combined, so you cannot use the priority of a trademark or design application to file a patent application later.

Author: Zsofia Pintz
Published: August 2020
Updated: July 2023