Sole proprietor to corporation: what actually changes in your books and filings

The short version

Once you incorporate, the corporation is a separate legal person from you — not a rebrand of your sole proprietorship. That means new bank accounts, a new GST/HST registration, a T2 corporate return instead of the T2125 you're used to, a structured decision about how you pay yourself, and (if you go the salary route) payroll registration. If you're still weighing whether to incorporate, read our guide on that decision first — this one assumes you've already decided and covers what changes next.

New entity, new bank accounts

The corporation is legally distinct from you, even if you're the sole shareholder and the only person who's ever touched the business. Practically, that starts with money: open a business bank account (and ideally a business credit card) in the corporation's name, and stop running corporate transactions through your personal or sole-proprietor accounts. Every dollar that moves between you and the corporation from this point on is either a salary, a dividend, a loan, or a shareholder transaction — and each of those has to be tracked as such. Clean separation from day one is the single biggest favour you can do your future self (and your accountant) at year-end.

A brand-new GST/HST registration

Your GST/HST number as a sole proprietor was tied to you personally. The corporation is a new legal entity, so it needs its own GST/HST registration — your old number doesn't transfer. Get the corporation registered before it starts invoicing with tax included, and update your invoicing, contracts, and any recurring billing to reflect the new number. If you were using a simplified remittance method as a sole proprietor, don't assume it carries over automatically either — eligibility and elections are tied to the registrant, and the corporation starts from scratch.

T2 filings replace the T2125

As a sole proprietor, your business income lived on a T2125 inside your personal T1. Once incorporated, the corporation files its own T2 corporate income tax return, separate from your personal return. Two deadlines to build into your calendar: the return itself is due within six months of the corporation's tax year-end, while any balance owing is due sooner — two months after the tax year-end for most corporations, or three months for a CCPC claiming the small business deduction that meets the CRA's conditions. That gap between "balance due" and "return due" catches people off guard: you can owe money before the paperwork proving how much is even filed. Our 2026 deadlines guide lays out the full calendar alongside your other filing dates.

Paying yourself now has structure

As a sole proprietor, "paying yourself" wasn't really a transaction — the business's income was your income. Inside a corporation, it becomes a real decision with two main paths: salary, which runs through payroll and is deductible to the corporation, or dividends, paid out of after-tax corporate profit and reported differently on your personal return. Many owners use a blend of both. We're deliberately not putting numbers on which is "better" here — the right mix depends on your income needs, the corporation's cash flow, and personal circumstances the CRA's general rules can't account for. It's worth a real conversation with an accountant rather than a rule of thumb pulled off a blog.

What matters operationally: whichever path you pick has to be documented and processed correctly. Salary needs a payroll account and regular remittances. Dividends need proper corporate resolutions and T5 slip reporting. Treating either as an informal transfer out of the business account is exactly the kind of shortcut that turns into a mess at year-end.

If you go salary: payroll registration

Paying yourself (or any employee) a salary means registering a payroll program account and remitting source deductions on a schedule set by your remitter type — which is based on your average monthly withholding amount from two years prior. New and small employers generally remit quarterly; most employers remit monthly; larger payrolls remit twice or up to four times a month. Get this set up before the first pay run, not after — retroactively fixing payroll remittances is far more painful than starting it correctly. If this is also your first time bringing on an employee (not just yourself), our payroll setup guide walks through the rest.

The transition-year gotcha

The calendar year you incorporate is split. Your sole-proprietor income up to the day the corporation takes over the business still gets reported on a final T2125 as part of your personal T1 for that year — you don't get to skip that step just because you incorporated partway through. From the incorporation date onward, activity belongs to the corporation and eventually lands on its first T2. Two sets of books, two returns, one calendar year. Missing this split — or worse, running the whole year's activity through only one entity's books — is one of the most common cleanup jobs we see in a first corporate year-end.

Why this is the best moment to start clean

Incorporation is a genuine reset. There's no history to untangle, no personal expenses buried in twelve months of transactions, no "I'll fix the categorization later" backlog — the corporation's books start at zero. That makes the first few months after incorporating the cheapest, easiest time you'll ever have to set up bookkeeping correctly: a proper chart of accounts, real monthly reconciliation, and a clear line between business and personal from the very first transaction. Do it now and every future T2 is a formality. Skip it and you're paying to untangle a mess later — at accountant rates, not bookkeeper rates.

This is also exactly the kind of moment we get called for. Our monthly bookkeeping starts at $200/month, HST filings included, and we handle year-end and T2 filings for Canadian corporations too — one team for the books and the return, so nothing gets lost in a hand-off between your bookkeeper and your accountant in year one.