Three form numbers come up the moment you start a business in Canada, and most people can’t tell you which one applies to them. Here they are in one breath: the T1 is the personal return every Canadian files; the T2125 is the business schedule that sits inside your T1 if you’re a sole proprietor; the T2 is a completely separate return that a corporation files as its own taxpayer.
The one thing to understand before any of the rest:
If you’re a sole proprietor, you are your business. Its income is your income, taxed on your return.
If you’re incorporated, the business is its own thing — a separate taxpayer with its own return, its own year-end and its own bank account.
Almost every other difference on this page flows from that one sentence.
The T1: everyone files this
The T1 is the standard personal return. T4s, investment income, RRSPs, credits. Doesn’t matter who you are in Canada, you file one. What changes is which pieces you attach to it — and if you run an unincorporated business, one of those pieces is the T2125.
The T2125: your business, inside your personal return
The T2125 is for sole proprietors and unincorporated partnerships. It’s a schedule of the T1, not a separate filing, so your business income lands on your personal return and is taxed at your personal rate alongside everything else you earn.
It has a few sections: information about the business, your income, your expenses by category, business-use-of-home, and capital assets. That last one catches people: anything you buy with lasting value — a computer, a camera, equipment — doesn’t go in as an expense; it goes in as an asset and is deducted over time. In our office anything over about $500 gets treated that way. Vehicle expenses need a log. Home office needs the square-footage calculation. If you sort your receipts into the T2125’s own expense categories as you go, your year-end is largely done before it starts — that’s the whole point of the routine in Getting your books tax-ready.
Self-employed filing date is June 15 — but any tax you owe is still due April 30. The later date helps with paperwork, not cash.
The T2: the grown-up older cousin
A T2 is the corporation’s own return, and it’s the T2125’s grown-up older cousin. Same idea — income, expenses, assets — but far more of it, and with one structural difference that changes everything: the books have to be continuous. Every closing balance in one year is the opening balance of the next. Bank, receivables, payables, shareholder loan, retained earnings — all of it flows forward. A sole proprietor can rebuild a year from a shoebox. A corporation can’t.
That’s why a spreadsheet stops being enough the day you incorporate. Corporate returns need real double-entry bookkeeping behind them, and the return itself is filed with software that costs more and asks more. I don’t recommend anyone tackle their first T2 themselves; the cost of getting it wrong is higher than the fee for getting it done.
The T2 is due six months after your fiscal year-end, and the tax is generally due before that — two or three months after year-end depending on the corporation. CRA’s page on corporation filing deadlines has the current rules.
Year-ends: December 31 for you, your choice for a corporation
As a sole proprietor you don’t get a say. Your business year is the calendar year, December 31, because it lives inside your personal return.
A corporation is different, and this is a decision people don’t realise they’re making. A corporation’s tax year can be any length up to 53 weeks, and the first one starts on the day you incorporate — so the date you incorporate and the year-end you pick on that first T2 set the pattern for every year after. Once it’s set, changing it needs CRA’s written approval, so it’s worth choosing on purpose.
You don’t have to choose December 31. Often it’s better not to. If your business has a busy season, put the year-end in the quiet stretch after it, when the books are clean and there’s time to close them properly. A retailer might choose January 31 so the holiday rush is fully counted and paid out; a summer-heavy business might choose September or October. It also spreads your own workload: a non-December year-end means your corporate return and your personal T1 aren’t landing in the same month.
The rules are on CRA’s page for determining your corporation’s tax year.
When incorporating actually makes sense
This is the question hiding behind every “T2125 vs T2” search. There are good reasons to incorporate.
You’re consistently profitable well past the point where you need all of it to live on — often somewhere north of $100,000 a year — and you’d rather leave money in the business to grow than take it all out as income.
More than one person owns the business, or someone wants to buy in. A corporation gives you shares to divide; a sole proprietorship gives you nothing to divide.
You need the liability separation, or a bank, landlord or major customer requires it.
And there’s one reason that used to be good and mostly isn’t anymore: incorporating to save tax. The big personal-tax advantages of running income through a corporation have been largely closed off over the last several years. If you’re taking everything out to live on, a corporation adds cost and complexity without much tax benefit. If you can leave money in and let it compound at the corporate rate, the maths can still work — but that’s a calculation, not a rule of thumb.
What it costs
Incorporating isn’t free and it isn’t one-time. There’s the set-up (a lawyer or an online service, and the price range is wide), an annual filing to keep the corporation in good standing with your province, and a corporate tax return every year that costs real money to have prepared properly. Add proper bookkeeping, because you can’t run a corporation on a spreadsheet. Those costs are worth it when the business is at the stage that justifies them, and a drag when it isn’t.
There is nothing wrong with being a sole proprietor. Stay there as long as it fits. When the numbers or the ownership change, that’s when we talk.
Not sure which side of the line you’re on?
If your books need to be corporation-ready — or you want to know whether they’d survive the jump — The Books Check-Up looks at them the way a reviewer would and tells you what’s solid and what isn’t, with a recorded video walkthrough within 7 to 10 business days. And if you’re weighing incorporation, get in touch — that decision deserves your actual numbers, not a blog post.