Alabama established a numerical county-code system for its license plates in 1941, with codes 1, 2 and 3 assigned to the three most populous counties of the time (Jefferson, Mobile and Montgomery), and codes 4 through 67 assigned to the remaining counties in alphabetical order. Code 70 was added in 1948 for replacement plates, followed in 1966 by code 80 for supplemental plates in counties that had run out of standard plates. The system remains in use today on passenger plates and some non-passenger types.
