Writing the applications on my own, five weeks until the one year on my US provisional runs out. Asking what must absolutely be included in the US non-provisional/regular patent and PCT applications.

Do I need to include only the specification, which I understand to be only description and drawings, when it is initially filed?

Can I add the claims in amendments later, and what are the time limits on adding to the initial filing?

If I sell publicly after filing only specifications, but before filing my claims amendments, will that affect what I can claim?

Sorry if this is repetition, but I seem to be finding varying answers, I'm out of time and critically under-resourced.

  • I have made a small edit to remove the phrase "first filing". This phrase typically refers to your earliest filing in a family (which in your case would be the provisional). I hope that's ok.
    – Maca
    Commented Jan 18, 2017 at 1:06
  • I haven't read Maca's answer (too long, no time, do later), but here's mine in short: more claims can be added later, everything else needs to go in
    – user18033
    Commented Jan 18, 2017 at 7:43

1 Answer 1


I will just include the mandatory recommendation here to get a patent attorney. If your invention is worth protecting, it's worth protecting properly. Otherwise, you're just throwing money away at filing fees with little chance of getting something at the end.

With that out of the way...

US Non-Provisional

What must a US non-provisional application include?

In short, you must have a description, a claim, and a drawing at minimum.

More formally, the requirements of an application are provided by 35 USC 111(a)(2):

(A) a specification as prescribed by section 112;

(B) a drawing as prescribed by section 113; and

(C) an oath or declaration as prescribed by section 115.

The specification comprises (35 USC 112(a)–(b)):

(a) IN GENERAL.—The specification shall contain a written description of the invention…

(b) CONCLUSION.—The specification shall conclude with one or more claims…

Can claims be added later?


MPEP § 506(I)(C) provides:

Filing dates are accorded to nonprovisional applications filed under 37 CFR 1.53(b) submitted without … at least one claim (for applications filed on or after December 13, 2013) …. In such cases, a notice is mailed by OPAP requiring the appropriate fees, claims (for applications filed on or after December 13, 2013) and for applications filed before September 16, 2012, the oath or declaration (which must include the names of all the inventors), accompanied by a surcharge (37 CFR 1.16(f)).

You will have to provide the claims shortly after though.

If I sell publicly after filing only specifications, but before filing my claims amendments, will that affect what I can claim?

No. If you sell the application such that the applicant is assigned to another party, then the obligation to add claims passes to whoever the new applicant is.

PCT application

What must a PCT application include?

PCT art 3(2) provides:

An international application shall contain, as specified in this Treaty and the Regulations, a request, a description, one or more claims, one or more drawings (where required), and an abstract.

Can claims be added later?

Not really.

PCT art 11(1) provides:

The receiving Office shall accord as the international filing date the date of receipt of the international application, provided that that Office has found that, at the time of receipt: … (iii)…(e) a part which on the face of it appears to be a claim or claims.

The consequences are provided by PCT art 11(2):

(a) If the receiving Office finds that the international application did not, at the time of receipt, fulfill the requirements listed in paragraph (1), it shall, as provided in the Regulations, invite the applicant to file the required correction.

(b) If the applicant complies with the invitation, as provided in the Regulations, the receiving Office shall accord as the international filing date the date of receipt of the required correction.

Thus your PCT application will be dated as of whenever you supply claims. If this is later than 12 months from the earliest priority claim (your US provisional), you will be too late: your priority claim will be invalid.


Thus there is some scope for not including claims in the US non-provisional immediately. However, this is a really bad idea.

When drafting your application, you should almost certainly start with your claims, and craft your description around the claims. This ensures that the description provides the necessary support for your claims.

Doing it in the other direction is risky. You would have to hope that the description contains the terminology and the features in a suitable manner that they can be used to form supported claims. While the US is somewhat forgiving on this, other jurisdictions (notably Europe) are much more restrictive. I have seen far too many applicants make this mistake, and get left with good inventions that will never get a patent due to poor drafting.

  • Thanks so much. I greatly appreciate all your time spent answering, and all the information. So to clarify, I can file the PCT with what claims I've got now, and I'll have 'now' as my filing date. If I amend claims later, those later claims will only count as having been filed at 'later'. The amendment will make my entire application start at the 'later' date? Will this 'later' amendment change the date of my 'now' claims to the date of my 'later' claims? And my question regarding sales should have read "If I sell my product after filing only specifications..."
    – Paul Paige
    Commented Jan 18, 2017 at 2:31
  • Will this 'later' amendment change the date of my 'now' claims to the date of my 'later' claims? No. Once your PCT application has received an international filing date, that date isn't altered by any amendment you make, e.g. under Articles 19 or 34 PCT. (Except if you're using the mechanism of Rules 20.3, 20.5 and 20.6 PCT, but these are really a stopgap measure in the event your PCT application is incomplete.) As Maca stated, the real issue is that in some jurisdictions, you could have trouble convincing the examiner that your amended claims are properly supported in the description.
    – Extraneous
    Commented Feb 2, 2017 at 20:37

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