Each of the 48 states of the United States of America plus several of its territories and the District of Columbia issued individual passenger license plates for 1931.^[1][2][3][4]

Passenger baseplates

Passenger  Car  Plates

Image	Region	Design	Slogan	Serial format	Serials issued	Notes
	Alabama
	Alaska
	American Samoa
	Arizona
	Arkansas
	California
	Canal Zone
	Colorado
	Connecticut
	Delaware
	District of Columbia
	Florida
	Georgia
	Guam
	Hawai'i
	Idaho
	Illinois
	Indiana
	Iowa
	Kansas
	Kentucky					Plates with an initial star (*) are truck plates.
	Louisiana
	Maine
	Maryland
	Massachusetts
	Michigan
	Minnesota
	Mississippi	Embossed white lettering and border on orange base; "MISS 1931" centered at bottom	none	1-234 12-345 123-456	1 to approximately 245-000
	Missouri
	Montana
	Nebraska	Red on gray; "1931 NEB" at right	none	1-12345 10-1234	Coded by county of issuance (1 or 10)
	Nevada
	New Hampshire
	New Jersey
	New Mexico
	New York
	North Carolina
	North Dakota
	Northern Mariana Islands
	Ohio
	Oklahoma
	Oregon
	Pennsylvania
	Puerto Rico
	Rhode Island
	South Carolina
	South Dakota
	Tennessee
	Texas
	Utah
	Vermont
	Virginia
	Washington
	West Virginia
	Wisconsin	Embossed yellow serial on dark blue plate; vertical "WIS" at left, weight class over "31" at right	none	123-456A	Coded by weight class	Weight classes are A, B, C, D, and E. Weight classes were dropped after 1931.
	Wyoming

Non-passenger plates

Non-passenger  Plates  

Image (standard)	Region	Type	Design & Slogan	Serial format	Serials issued	Notes
	Wisconsin	City bus	Embossed yellow serial on dark blue plate; unknown format		Coded by weight class
		Dealer	Embossed yellow serial on dark blue plate; vertical "WIS" at right; embossed solid star over "31" at left	1234A	Dealer number and plate number	The number is the dealer number, the letter is the plate number for that dealer
		Interurban Bus	Embossed yellow serial on dark blue plate; unknown format		Coded by weight class
		Motorcycle	Embossed yellow serial on dark blue plate; unknown format	A1234	A 1 to approximately A1000	Used on regular motorcycles
				B123	B 1 to approximately B500	Used on motorcycles with sidecars
		Municipal	Embossed blue serial on yellow plate; vertical "WIS" at left, vertical "1931" at left	1234	1 to approximately 5200	Motorcycle version also available
		Trailer	Embossed red serial on cream plate; "30" over "31" at left, vertical "TRALR" between date and serial; vertical "WIS" at right	A 12	Coded by weight class	Weight classes same as truck
		Truck	Embossed red serial on cream plate; vertical "WIS" at right "30" over "31" at left	A12345	Coded by weight class	Weight classes were A, B, C, D, E, and F