Soundex Rules

Code Key Letters and 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. A name yielding no code numbers, as Lee, would thus be L000; one yielding only one code number would have one zero added, as Ebell, coded as E140. Never are more than three digits used, so Ebelson could be coded as E142 not E1425.

When two key letters (or equivalents) appear together, or one key letter immediately follows or precedes an equivalent, the two are coded as one letter, by a single number, as follows: Kelly, coded as K400; Buerck, coded as B620; Lloyd, coded as L300; and Schaefer, coded as S160.

When several surnames have the same soundex number they are arranged alphabetically by the given name.

Prefixes to surnames as: VAN, VON, DI, DE, LE, D, DELA, or DU are usually included in the soundex coding. Example:

Name Letters Code VANMETER n,t,r V536 VANJOHNSON n,j,n V525 VONVALKENBURG n,v,l V514 DEBARTOLA b,r,t D163 DECORTEZ c,r,t D263 LEMOND m,n,d L553 DHEMECOURT m,c,r D526 DELAROSA l,r,s D462 DUBOIS b,s D120

Use caution, such prefixes to surnames are sometimes disregarded in alphabetizing and coding.

CAUTION!
Soundexes are a valuable tool but they are not without problems. Since the first letter of each name is used to assign it to a group, any misreading of that letter can affect its placement in the soundex film. The letters: S and L, R and K, H and K are often mistaken for one another. In addition, surnames often have more than one valid spelling:

Vasquez vs. Basquez
Cole vs. Kohl

It was also a common practice for families to "Americanize" their names when coming to the U.S.

Mueller vs. Miller
Schmidt vs. Smith
Langinsky vs. Lang