How many license plate characters does your state have?

[tchafe1978]

Wisconsin in the past couple years has gone form 6 characters to 7 because the state ran out of plate number combinations.  I have two older cars with plates with 6 characters and a newer car bought this year that has 7.

[ftballfan]

Michigan has mostly 7. The plates could fit 8

[DTComposer]

California has 7 characters, a number followed by three letters and then three more numbers.

Or, to answer the question in another way, there are 40 characters that appear on California plates, the letters A to Z, the numbers 0 to 9, and four symbols: hearts, hands, stars, and plus signs.

California adopted this method in about 1980. It seems to take about 6 years to move through a leading number (i.e. moving from 1 as the first number to 2). They're currently nearing the end of the 7 series.

Prior to this they were on a six-character system, three numbers then three letters.

[zachary_amaryllis]

colorado has gone all over the place over the years.
when i was a kid, it was xx-1234, but sometimes xx-123, xx-12 or even xx-1
then they went to xxx-123 for a whilte.
then xxx1234 (no hyphen) but it was deemed too hard to read
for a while, it was 123-xxx.
now they're doing xxx-123 again, but i've also seen some that are like xxx-x123.

plus we have about a million specialty plates.

[jakeroot]

plus we have about a million specialty plates.

If I'm not mistaken, Colorado has the most number of vanity plates. There's around 100, when you add up alumni, speciality groups, military, and others (minusing those that are the same plate with slightly different vertical codes).

The only thing I don't like about Colorado is that their fleet plates are radically different from standard plates. Thus rental cars are very easily identifiable. For more than a few reasons, I'm not a fan of this.

[Roadwarriors79]

Arizona has been using 7 characters on their standard plate since 2008. Until recently, the current plates used the ABC1234 format. Now, there are just a bunch of random letters and numbers. This randomness has carried over to all the various specialty plates too, from what I have observed.

[SP Cook]

WV has a unique, and incredibly wasteful system of 6 characters. 
First Series: *L NNNN
Second Series *LL NNN
Third Series *NL NNN

Where * can only be the numbers 1-9 and the letters O N or D, indicating the month the plate expires.  Obviously this is inefficient in two ways.  First the number of possible combinations is far smaller; and the DMV is required to maintain 12 types of stock where one would do.  The third series will be exhausted in about a year, no idea after that.  They said they were going to issue a new plate with a single series, but never did, about 10 years ago.