Soundex

The soundex system is a method of grouping related words, or in this case surnames, to help eliminate spelling variations that occur. Soundex was used by the U.S. Works Administration Project during the Great Depression to encode census records. While this was a make-work project, that effort has helped genealogists find ancestors.

How does it work?

The surname is encoded using the following rules and all records associated with that code are grouped together in the index. The index is usually sorted by the actual surname and given name, if known.

How long is the code?

The code has 4 positions for census work. Other records may use additional positions, but the census always uses 4.

Rules

1. The first letter of the name is moved to the first position in the code
   • Notice that the first letter is not changed to a number
   • If the name includes O, Mc, Mac, Le, La, De or Von the name may have been coded with or without the prefix; check both groups to be safe
2. Remove the following letters from the name: a, e, i, o, u, y, w, h
3. Change all remaining letters to numbers using the table below
   • If two letters code to the same number, only code the first letter
4. When done coding the name add zeros (0) to create a 3-digit number

Examples: