Is a professional accountant required by law to do annual taxes/reports/filings for a federal or a provincial corporation in Canada? I am about to incorporate my company but don't have enough money to hire any accountants at this stage. Thanks.
No, an accountant is not required. I've done my Ontario Provincial T2-Short my self every year since 2006, it is not even that complicated. You only really need an accountant if you start getting in to a lot of accounting tricks etc.
You can also buy off-the-shelf software to do your T2 Corporate tax return for a few $100 from Quickbooks or the like, but it is easy enough to do by hand.