It depends, there are actually 2 different vaccines available in Canada--one is a three year and it's the most common, the other is a one year that was developed to be used in dogs and cats with vaccine reactions--but it doesn't last nearly as long (or so I've heard)
It is still legal and normal for a vet to "require" that you vaccinate every year. For instance I still get a new vaccine certificate each year from Ross, but it says that Havoc is protected until 2008. KWIM? Technically a boarder guard could figure out that the dog hasn't been vaccinated this year, but it's completely fightable--that said--a lot of vets don't do it this way.
Let me know if you want Ross's number though, he's a great vet, very laid back and he does most of his own emergency work.