Basic Soundex Coding Rule




Every soundex code consists of a letter and three numbers, such as W-252. The letter is always the first letter of the surname. The numbers are assigned to the remaining letters of the surname according to the soundex guide shown below. Zeroes are added at the end if necessary to produce a four-character code. Additional letters are disregarded.
 

Examples:

Lee is coded L-000 (L, 000 added).
Washington is coded W-252 (W, 2 for the S, 5 for the N, 2 for the G, remaining letters disregarded).

Soundex Coding Guide

Number Represents the Letters

1       B, F, P, V
2       C, G, J, K, Q, S, X, Z
3       D, T
4       L
5       M, N
6       R

Disregard the letters A, E, I, O, U, H, W, and Y.



Additional Soundex Coding Rules:
 

Names With Double Letters:

If the surname has any double letters, they should be treated as one letter.

Example:
Gutierrez is coded G-362 (G, 3 for the T, 6 for the first R, second R ignored, 2 for the Z).



Names with Letters Side-by-Side that have the Same Soundex Code Number:

If the surname has different letters side-by-side that have the same number in the soundex coding guide, they should be treated as one letter.

Examples:
Pfister is coded as P-236 (P, F ignored, 2 for the S, 3 for the T, 6 for the R).
Jackson is coded as J-250 (J, 2 for the C, K ignored, S ignored, 5 for the N, 0 added).
Tymczak is coded as T-522 (T, 5 for the M, 2 for the C, Z ignored, 2 for the K).
Since the vowel "A" separates the Z and K, the K is coded.



Names with Prefixes:

If a surname has a prefix, such as Van, Con, De, Di, La, or Le, code both with and without the prefix because the surname might be listed under either code. Note, however, that Mc and Mac are not considered prefixes.

Example:
VanDeusen might be coded two ways:
V-532 (V, 5 for N, 3 for D, 2 for S) or D-250 (D, 2 for the S, 5 for the N, 0 added).



Consonant Separators:

If a vowel (A, E, I, O, U) separates two consonants that have the same soundex code, the consonant to the right of the vowel is coded.

Example:
Tymczak is coded as T-522 (T, 5 for the M, 2 for the C, Z ignored (see "Side-by-Side" rule above), 2 for the K).
Since the vowel "A" separates the Z and K, the K is coded.

If "H" or "W" separate two consonants that have the same soundex code, the consonant to the right of the vowel is not coded.

Example:
Ashcraft is coded A-261 (A, 2 for the S, C ignored, 6 for the R, 1 for the F). It is not coded A-226.