The Soundex System

In the late 1930s the federal government, in its efforts to index the U.S. censuses, devised the Soundex system. The names from the census records were extracted, coded and placed onto cards. After coding, the cards were then sorted sorted according to certain Soundex rules. The result was a listing of people from the censuses whose names, although spelled differently, were grouped together because they "sounded" alike.

Finding the Soundex code for a given surname can be one of the most valuable tools in genealogical research, since it facilitates using government documents that are arranged by the Soundex Index. Other federal records that have been indexed using this system include ship passenger lists and military records, and many state and local records are soundexed as well.

The Soundex system is useful because it allows you to find a person in the census even though their name may have been recorded under various spellings. The advantage to this type of index is that phonetic spellings are grouped with what might be considered standard spelling for the name. This helps to compensate for an unusual spelling of the surname. Surnames that sound the same but are spelled differently, like Smith and Smyth, have the same code and are filed together in the index.

To locate a particular surname in the Soundex index, you must first find its code. Finding the Soundex code for a person's name is easy to do. Every Soundex code consists of a letter and a 3-digit number. The letter is always the first letter of the surname. If the name is Kuhne, for example, the index card will be in the "K" segment of the index. Then numbers are assigned to the remaining letters of the surname. The code for Kuhne, worked out according to the system below, is 500.

The Soundex Coding Guide

The Number:	Key Letters or Equivalents
1	b, p, f, v
2	c, s, k, g, j, q, x, z
3	d, t
4	l
5	m, n
6	r
The letters a, e, i, o, u, y, w and h are not coded. The first letter of a surname is not coded. Every Soundex number must be a 3-digit number.

Line 1:

Line 2:

Steps:

On line 1, write the surname you are coding, placing one letter in each box.
On line 2, write the first letter of the surname in the first box.
On line 1, disregarding the first letter, slash through the remaining letters a, e, i, o, u, w, y and h.
On line 2, write the numbers found on the Soundex Coding Guide for the first three remaining unslashed letters. Add zeroes to any empty boxes. Disregard any additional letters.

Most Surnames can be coded using the four steps mentioned above. However, for names with prefixes, double letters or letters side by side that have the same number on the Soundex Coding Guide, some additional rules apply.

Additional Soundex Rules

Names with Prefixes

If your surname has a prefix (like Van, Von, De, Di or Le) you should code it both with and without the prefix because it might be listed under either code. The surname vanDevater, for example, should be coded in the following two ways:
V531 D153
(Mc and Mac are not considered prefixes.)

Names with Double Letters

If your surname has any double letters, they should be treated as one letter. Thus, in the surname Lloyd, the second L should be slashed out; in the surname Gutierrez, the second R should be slashed out.
Lloyd: L300 Gutierrez: G362

Names with Letters Side by Side that Have the Same Number on the Soundex Coding Guide

Your surname may have different letters that are side by side and have the same number on the Soundex Coding Guide; for example, PF in Pfister (1 is the number for both P and F); CKS in Jackson (2 is the number for C, K, and S). These letters should be treated as one letter. Thus is the name Pfister, F should be slashed out; in the name Jackson, K and S should be slashed out.
Pfister: P236 Jackson: J250

Source: The World Book of Surnames, copyright MCMXCVI by Halpert's Family Heritage.

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