Finding the serial number on a piano depends on a number of factors, mainly what type of piano is in question; a stand-up piano's serial number is normally found stamped in the plate at the top of the piano or a window close to it, while a grand piano's number is stamped in the V-shaped area between the tenor and bass sections, it also can be placed on the soundboard under the strings. A piano's serial number gives the owner or perspective buyers information on when the piano was manufactured.
While the most common places for a piano´s serial number are listed above, different manufacturers place their stamps in different places. Some good resources to check when trying to determine a piano's age, where it was built and the circumstances around its history, as well as how to determine what its value is are as follows.
"The Pierce Piano Atlas" lists more than 12,000 pianos including details about where to find serial numbers, locations about where the factories that made them, a history of the companies and details about the manufacturing of the instruments in general.
"The Piano Book" is an industry-wide resource for buying and selling pianos. It list practical information about the workings of a piano as well as details and comparisons about all of the brands and makes sold in the United States.