File Patent Applications Quickly to avoid On Sale Bar

Patent Priority

Filing a patent is required to not only obtain priority over later inventors but also to prevent patent rights from being lost as a result of the Patent On Sale Bar Doctrine. Patent rights are based on priority.  Generally, patent rights go to the first inventor.  However, as a result of the American Invents Act (AIA), America is now a first to file country.  This means that the patent rights go to the first inventor to file a patent application covering the claimed invention.  The first inventor to file an application has priority over a later inventor.  However, in order to obtain a patent and enforce a patent, a patent must be filed within twelve months of it being known by others, this is referred to as the patent On Sale Bar Doctrine. Recently, one court held that an initial negotiations letter related to a medical sheath constituted a offer for sale, invalidating a patent because it was not filed within twelve months of the letter.

On Sale Bar requires that an invention must be filed within 12 months of disclosure.


In order to qualify as a patent, an invention must meet four requirements: (1) it must be of patentable subject matter, (2) it must be useful, (3) it must be novel, and (4) it must be non-obvious.  Generally, novel means new.  To be new, an invention must not be.  An invention is not new if it:

  • Was described in a patent issued anywhere in the world for more than 12 months.
  • Was described in a printed publication published anywhere in the world for more than 12 months.
  • Was publicly used in the US for more than 12 months.
  • Was offered for sale in the US for more than 12 months prior.

If any of these occurred, then the patent is not novel and any patent which issued may be challenged.

On Sale Bar

The general rule is that the patent will go to the first inventor who meets the four requirements above and is the first to file a proper application covering the invention.  However, if the invention was on sale in this country more than one year prior to the date of the patent application, then the patent will be barred based on the on sale bar. The determination of whether an invention was on sale if often a two-pronged test.  The first prong is whether the invention is the subject of a commercial offer for sale.  Was the invention offered for sale?  If so, then any patent covering the invention may be invalid.  The second prong is related to the timing of the offer.  At the time of the offer for sale, was the invention ready for patenting? If so, then the invention was on sale.  Usually, this second prong focuses on the status of the invention.  Some follow-up questions for determining if the invention was sufficiently disclosed include determining whether the invention was “reduced to practice” or whether the inventor had drawings prepared covering the invention.

In some cases, a commercial sale to a third party subject to a confidentiality obligation may still place the “on sale.” A sale or offer of sale need not make an invention available to the public.  For the On Sale Bar to apply, the issue is whether the invention had been sold, not whether the details of the invention had been made available to the public or whether the sale itself had been publicly dis­closed. In fact, secret sales can invalidate a patent.

If you have any questions about your invention and the impact of the on sale bar on the validity of your patent, contact one of our patent attorneys.