The KM number frequently cited on eBay auctions, as well as the websites of world coin dealers, is the Standard Catalog of World Coins reference number. KM stands for Krause and Mishler, the original authors of the Standard Catalog of World Coins. The catalog, now expanded to five volumes, attempts to list, picture and price most coins issued since 1600. Each of the five volumes covers the coins issued in a particular century, thus there is a volume for the 17th, 18th, 19th, 20th and 21st century. The volumes are updated about every one to three years. The catalog is usually soft-cover, and due to its thickness (often running over 2000 pages), it is sometimes referred to as “The Telephone Book”. It is also commonly refered to as the Krause catalog. When collectors or dealers of world coins refer to a coins catalog price, they are usually referring to the price in the Standard Catalog of World Coins.
Each type and denomination of coin from a country is assigned a KM number. Many collectors use the KM numbers as an easy way of keeping track of coins they want or have. By having the catalog and knowing the country name and KM number, collectors can look up the coin in the Standard Catalog of World Coins (though it is VERY helpful to also know the denomination, as the numbers are assigned chronologically but the coins are listed by denomination in the catalog.) The exact information included for a particular coin varies, but will often include a picture, metal content, including the amount of precious metal for silver and gold coins, description of the design, mintage figures, and estimated retail prices for the coin in multiple grades.
The retail prices are the most controversial aspect of the catalog. The catalogers depend on a number of volunteer contributors to submit pricing information. Some contributors think very highly of their specialty and submit high catalog values. Other areas may lack active contributors, so prices do not get updated to reflect current market activity. And sometimes I just don’t understand how they get the prices listed. The prices should be understood as a person’s estimate of a coins value, and should not be taken as Gospel Truth. I list my coins at a fraction of their catalog value, because I feel the true retail price should be substantially less than the current catalog value. I also offer coins at well above the catalog value, because in my experience the coin is a lot scarcer than the catalog indicates, or the catalog prices for that issue have not been updated for many years. Interestingly the items priced well above catalog value tend to sell out faster than the items that are heavily discounted from the catalog price!
The World Coin Price Guide is a complete catalog of values for World coins from 1600 to date. Created by NGC and Krause Publications’ NumisMaster, the price guide pages are arranged by Krause catalog numbers and include values, images and specifications such as weight, composition, engraver and current bullion values. Found at NGCcoin.com, it is the most comprehensive online valuation guide available, and is free to all users.