According to The Soundex system, variations of the Decker surname include:
DACRE DAGGER DASHER DECKER DECUIR DICKER
DISHER DOCKERY DOCWRA DOZIER DUGGER
The Soundex system used by genealogists to identify variations of names. It is used to index names in US Census records, which often contained misspellings.
The Soundex code for Decker is D260.
Find the Soundex code and known variations for any surname here: (Alternate link)