Illustration: cartoonstock.com

It’s one week before the big trade show, and after months of hard work you have just completed a fully functional prototype of your new product. Showing it off at the conference will do wonders for your career and put your small start-up company on the map. Then reality hits like a jolt from a Tesla coil: your new product is also an invention. You must protect your rights to it immediately, before the conference. So you write your own provisional patent application, file it with the U.S. Patent and Trademark Office (USPTO), and go to the show feeling like you’re wearing Superman’s cape.

Beware: there may be kryptonite close by.

The Provisional Application for Patent was introduced a dozen years ago to make initial patent protection more affordable to small businesses. A provisional gets you to “patent pending” status faster and cheaper, at least in the short run, than a standard, or “utility,” patent application. It also gives you a whole extra year of patent-­pending status without sacrificing a single day of the life of any patent that may issue from it. It does not, however, get you to an issued patent faster.

The advantages are clear. The extra year gives you time to commercialize your invention before incurring any of the costs of a full-blown utility patent application. At the same time, it lets you establish your priority to the invention, even though the USPTO has not even begun to examine the validity of your claim.

There are also dangers, however, many of which become evident only after the year has elapsed or when a patent infringement lawsuit intervenes, putting the provisional patent application under a judicial microscope. By then the uninformed inventor may learn too late that he or she should have taken more care with the provisional application, in matters as large as the wording and as (apparently) small as the accompanying sketches or photographs.

Of course, the entire purpose of a provisional application is to “grab” a filing date and a “patent pending” designation. The inventor can file pro se, that is, without an agent.

At least six things can go wrong:

You could put an embarrassing document just a mouse click away from everyone. You might believe that you can be a little loose with the application—after all, it’s not published. Or is it? When someone files a utility patent application that claims priority to the provisional patent application or that makes reference to the provisional patent application, the provisional becomes public record. That means your hastily prepared application, along with its paper-napkin drawings, will be just a mouse click away. So you had better think about the image you might be about to portray to the world. What would potential investors think of it? How about your competitors or potential infringers?

You could lose your early filing date. Provisionals are still patent applications, so they must comply with the same requirements as utility applications. Here is where you can get into real trouble. The law requires that any patent application describe how to make and use the invention in such detail that anyone “skilled in the art” could do likewise. It also requires that the best mode of carrying out the invention be described in the application. So if your provisional doesn’t meet both conditions, it cannot be relied on to grab you an earlier filing date. Basically, that would mean that you never really had an earlier filing date, and someone else’s work, though it comes after your own, may yet knock you out of the game.

You could end up with narrow claims. Returning to our first example, you hurriedly file a provisional application before the trade show, describing exactly how you made your prototype. Then, after the show, you continue your engineering work and a year later find that your prototype offered only one narrow and specific way to solve a much bigger problem that has a much larger potential market share. Now you face a dilemma: if you file a utility application based on the narrow definition in your provisional, your resulting claims may have little commercial value. If instead you file a broad utility application without claiming priority to the narrowly defined provisional, someone could beat you to the punch by filing a patent application before you file your utility. Had you only put the time and thought into a broad and well-crafted provisional patent application, you wouldn’t be in this mess.

You could lose foreign rights. If you plan to file in other countries, your provisional patent application must meet their requirements. A lot of countries require that the document establishing priority (in this case, your provisional) provide nearly exact wording for what is later claimed in the foreign patent application. Fail to do so and you may lose your claim of priority and even lose your rights to a patent in that country.

You could cede patent rights to a competitor. You filed a quick and dirty provisional four years ago and then hired a patent practitioner to prepare, file, and prosecute “the real deal” utility application. You are enjoying the fruits of your labor with an issued patent—until you are forced to defend it in court. Now your quick and dirty provisional is being taken apart word for word in court, and it appears that it does not meet the enablement requirements of the law. You are at least comfortable that you still have your utility patent with the later priority date—until you find out that your competitor filed a utility application a week after your provisional application and before your utility application. And you don’t have any other proof that you invented first. You could now be without patent rights, and your competitor could later have an issued patent. Not good!

You may be barred from patenting your own invention. Another peril that can stem from provisional applications involves what is known as statutory bar dates. In the United States, an inventor must file a patent application within one year after a public disclosure of the invention, or the inventor is barred from obtaining a patent. So, if you file a provisional application after disclosing your invention in public, wait the full year before filing a utility application and find that your provisional application cannot establish your claim to priority, then you cannot claim the benefit of your provisional filing date. In this situation, the filing date of your utility application is past the one-year anniversary of the date you disclosed your invention to the public, so you will be barred from patenting your own invention. This state of affairs often doesn’t become clear until your patent is attacked in an infringement lawsuit.

New Railhead Manufacturing, a company in Weatherford, Texas, learned that lesson the hard way when it filed a provisional patent application for an asymmetric drill bit. It then lost not only its infringement suit against Vermeer Manufacturing Co., in Pella, Iowa, and Earth Tool Co., in Oconomowoc, Wis., but its patent as well, in a case decided in 2002 by the U.S. Court of Appeals for the Federal Circuit.

The moral of the story? The provisional patent application is still fairly new, and that alone should give you pause. It can be an effective and nifty tool if used properly, but it can create major problems and a false sense of security if written or illustrated poorly. File a provisional patent application if you must—but meet the same requirements as you would if you were filing a nonprovisional application as that first step.