Most of the consumer class printers available here have a max paper path width for letter (A) size, 8.5 inch. That's wide enough to push an A4 through or of course anything smaller. The next step up (another $200? US or more) gets you a 13 inch wide path, which will handle A3 or the "A3+" or US "Super B." both of the latter are 13 inch narrow side.
The few Super B size printers I've found here are $300+ (US) and few people get them for home use. Surprisingly, perhaps, it's easier to get a color printer over 8.5 wide than a laser (B/W) type.
Anything that will print on wider than 13" (330 mm) is usually called a "plotter" rather than a printer.
Just thought perhaps the big 'uns were more common elsewhere.