The International Watch Co., also known as IWC or IWC Schaffhausen for the Swiss city where the watches are manufactured, is perhaps the top watchmaking company consistently producing top-quality luxury watches since its inception in 1868. IWC pocket watches are generally easy to identify by examining the dial and movement for the “International Watch Co.” logo. However, IWC also produced an extensive range of military pocket watches and watches for dealers and even other watchmakers that don’t have the IWC plainly embossed on the dial. These pocket watches need extra examination to determine authenticity.
Use the jeweler’s loupe to inspect the dial of an IWC pocket watch. The most obvious identifier is “International Watch Co.” embossed in elegant script below 12 o’clock. Many models will have “Schaffhausen” stamped below IWC’s name.
Use a blunt case blade to pry open a snapdown case back or pop open a hinged case back with your thumb to view the movement, which is the spring-loaded engine that regulates the pocket watch.
Use the jeweler’s loupe to inspect the movement. At the edge should be “International Watch Co.” or “Int’l Watch Co.” in script.
Inspect the serial number, which should be located above the name or at the opposite side of the movement. A number follows “No.” Serial numbers 10,001 through 50,000, for example, denote an IWC pocket watch manufactured between 1890 and 1896.
Examine the crown, which is the winding knob on the case edge at 3 o’clock. Older models have a “fish” symbol. Newer generations have “PROBUS SCAFUSIA” in raised letters at the top and bottom of the crown with “IWC” in the center.
Open the case back of the IWC pocket watch as instructed in Section 1, Step 2. "Schaffhausen" is stamped on top of the movement or under the balance cock, which is a bridge under the regulator. The name should be visible without removing the balance cock. This is an IWC watch. IWC manufactured movements for many years in the early 20th century for Stauffer, Sons & Co. in London. The dials identified these pocket watches as “Peerless” with an “S&Co.” stamp. Yet these are true IWC pocket watches.
Open the case back of an early 20th century Ulysse Nardin pocket watch. Examine the movement as instructed in the previous step. The watch is a genuine IWC if “Schaffhausen” is stamped on the movement or under the balance cock. It was manufactured for Ulysse Nardin.
Examine the movement with a jeweler’s loupe of an IWC military watch. “International Watch Co.” is likely stamped on the dial, but inspection of the movement under the balance cock is necessary to identify it as a “Schaffhausen.” On early 20th century U.S. military pocket watches, for example, “Corps of Engineers” is stamped on the case back.