Not necessarily.
The expiration month is tied to that actual number they assign. (The numbers, not the letters) I won't go into detail, but it's designed so we can tell at a glance if the decal is actually for the assigned number, or belongs to another boat.
AAAHHHhhhh.....That explains why mine expire in April, when the boat was first registered new in Sept or Oct. I was corn-fused. I thought maybe everyone expired in April, but then I saw that wasn't the case. Now I get it!!! Thanks!
RTJas