From PCT to US National Stage: How to get the initial filing right

Before filing a US national stage patent application

A PCT application provides several benefits beyond merely delaying the costs of filing individual national stage applications in desired countries. By taking advantage of these optional strategies while the PCT application is pending, an applicant can place their patent application in a more strategically effective position for entering the US national stage. Let’s discuss what can be done to optimize a PCT application for US national stage filing.

Amending PCT claims based on prior art search

One significant benefit is a prior art search conducted prior to the national stage deadline. By reviewing the prior art search results contained in the International Search Report (ISR), an applicant can strategically amend the PCT claims before the national stage deadline. In particular, the PCT claims may be amended to include additional features not shown or suggested in the PCT prior art search report.

Requesting a favorable PCT opinion on allowability of claims

The first PCT prior art search done by the International Search Authority (ISA) will show which claims meet the following three requirements of allowability:

  1. novelty;
  2. inventive step (PCT equivalent of nonobviousness); and
  3. industrial applicability (usefulness).

Since most claims will have some usefulness, PCT search reports will most likely find novelty or inventive step lacking in at least some of the claims in a typical PCT application. Filing an amendment and a Chapter II (“chapter two”) Demand will give the applicant a second chance at obtaining a favorable ruling indicating that the claims meet all three conditions.

If any claims meet all three conditions, the applicant may then consider filing a PPH request in a participating national stage country. Even if PPH is unavailable in a particular country, amending the claims prior to national stage entry will place the claims in a more allowable condition for examination. At least, the examiner in that country’s patent office may have to search harder for closer prior art.

Remove multiple dependencies and reduce claims to 3 independents and 20 total

The USPTO charges a hefty government fee for the mere presence of multiple dependent claims. If there is even one multiple dependent claim, a fee of $430 will apply to a small entity (double for a large entity). Furthermore, multiple dependent claims will add to the total number of claims which may then incur excess claim fees.

The USPTO charges excess claim fees for each independent claim above three, and for total number of claims in excess of 20. Paying such excess claim fees might not worthwhile given the high likelihood of an eventual Restriction Requirement in a case with a large number of claims. A Restriction Requirement will limit the number of claims that the examiner will review, thereby wasting the money paid for the excess claims.

Expect to disclose prior art throughout US national stage prosecution

The USPTO is unlike many foreign patent offices in that US patent laws require applicants to disclose known prior art that is material to the patentability of the claims. In other words, you have to disclose what you know is relevant in the prior art. This duty of disclosure will mean that you will have to submit at least one Information Disclosure Statement (IDS) citing the prior art uncovered in the PCT application.

If the PCT applicant has counterpart applications in other foreign countries, then any prior art uncovered by the foreign patent offices will also need to be disclosed if not already cited in the PCT application.

Though an IDS need not be filed concurrently with the initial filing, it can be efficient to do so. It would be a mistake, however, to have a “one and done” mentality where you assume that the first IDS is the only mandatory disclosure of prior art. To the contrary, you will need to file supplemental IDS submissions in a timely manner whenever new and relevant prior art has been made known to the applicant.

Need to file a US national stage application?

Contact US patent attorney Vic Lin at to request a flat fee initial filing estimate for your US national phase application.

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