I've started a freelance web development company. Up to now all my clients have been based in Canada and I have been collecting taxes for the government.
I have been contacted by a Pub in the UK, which is looking to have a website developed. What taxation laws does a Canadian need to abide by when selling media to buyers in the UK?
Tax International Web Services Exporting
You should probably talk to an accountant, but from my personal experience in the UK operating through a limited company, the only difference in terms of tax are charging Value Added Tax (VAT). If your company is in the UK and provides services or products to non-EU country, you cannot (or at least should not) charge VAT. I am guessing something similar applies to a Candian company supplying services to the UK.
Otherwise, to my (limited) knowledge, all income, regardless of its source should be taxable in your country (or any country you operate from).