A patent application was originally drafted in a language other than English and filed in a country other than the US. It was subsequently translated into English and made a PCT application and entered into US national phase. During the US examination, it was discovered that the translation into English was poor, leading to comprehension problems. There is a real risk that, due to the bad translation, the application might be rejected as unclear, or might be accepted but turn out not to cover the invention as intended.

Up to what point in the procedure can the translation be revised to match the original text? What procedure should the applicant follow?


2 Answers 2


Since the US application is the national phase of a PCT application, the specification of the PCT application is the specification of the US application. The poor English translation is unfortunate, but the fact remains that the content set forth in the original PCT application should be the content that is represented in the US national phase application. In this regard, correcting the poor English translation merely amounts to rephrasing or correcting an obvious error (see MPEP 2163.07). Corrections to the specification of the US national phase application can be made in order to ensure that its content is the same as the content of the PCT application, as described below.

The specification of the US application can be amended at anytime up until the issue of the patent by filing an amendment with the USPTO according to the guidance set forth in MPEP 714.

If the patent has already issued, then the specification may be amended by filing a reissue application in order to correct the issued patent. A common ground for filing a reissue application is that the specification contains inaccuracies (see MPEP 1402). During prosecution of the reissue application, an amendment may be filed with the USPTO that amends the specification according to the guidelines set forth in MPEP 1453.


During prosecution the specification can be amended at any time as long as it conforms to 37 CFR 1.121 and 35 USC 112.

The main problem I would see in amending after prosecution has started would be "new matter".

This also appears to be relevant:

Where a U.S. application as originally filed was in a non-English language and an English translation thereof was subsequently submitted pursuant to 37 CFR 1.52(d), if there is an error in the English translation, applicant may rely on the disclosure of the originally filed non-English language U.S. application to support correction of an error in the English translation document.

From MPEP 2163.07

Overall, it would be best to have the best translation made before the application is filed so that none of these problems would occur.

  • Your first quote from MPEP 1893.01(d) is referring to amendments made to the translation that result in a translation that is different from the content of the original foreign language document. Thus this quote is not relevant to merely correcting a poor translation. The second quote is very relevant however.
    – Travis G
    Commented Sep 21, 2012 at 20:53
  • You're right, I'm going to edit the answer to remove this portion. Thanks.
    – Plepleus
    Commented Sep 21, 2012 at 20:57

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