Saw a car on the 18th Jan that boasted a road tax dated 31st Jan 2014 - always thought it was impossible... the background colour was used quite recently too, it's a red / pink. The car was a 60 reg Vauxhall. What don't I know here ?
Their previous disc would've expired on the 31st Jan 2013. They've bought the new disc online in advance and just put it in the window now.
It's also possible to get 12+ months through a dealer when buying a new car, ie the remainder of the current month plus 12 months onwards.
Many dealers can't be bothered to do this though as they get nothing out of it.
A guide to how much VED you will need to pay on your car.