Yes, Canada's is quite different - I did look into that bfeore I left Canada. My 2008 tax return had the box checked that said "this is my last tax return", and then I went through the process to make sure that my ties to Canada were severed for tax purposes - closed bank accounts, closed credit cards, transferred my drivers' license to a British one, cancelled my OHIP, etc... Canada determines residency for tax purposes slightly differently from other countries, so you have to make sure you have your ducks in a row. My understanding with the UK is that they are much less strict with that, you simply don't pay tax if you are not a resident, I don't think they go through the same audit etc. I had no issues when I re-filed my tax return this year, my first one in 5 years.
(Amusingly, my parents had a letter from CRA addressed to me saying they were missing my 2011 tax return. I called them to tellt hem that I was not a resident in Canada, had not filed since 2008, and well done on noticing they didn't have a 2011 tax return, but no mention of 2009 or 2010, haha. However they could see that my 2008 file had the "this is my last tax return" box ticked, so it ended up being fine.)
