- The moment closing happens, an individual seller has typically realized a capital gain or loss (if shares were sold personally) and a corporate seller has typically realized a gain or…
- - Personal income tax return reporting the capital gain, for the tax year in which the sale closed.
- - A corporate income tax return reporting the gain or loss on the assets sold, for the corporation's relevant taxation year.
Closing day ends your ownership of the business, but it doesn't end your paperwork. Depending on how the deal was structured, a seller can spend the following months (and sometimes the following tax season) dealing with returns, elections, and reconciliations tied directly back to the sale. Knowing roughly what's coming — and that it belongs with an accountant, not a general internet search — helps you plan for it instead of being surprised by it.
This article outlines the kinds of filings sellers commonly need to address, and how the answer shifts depending on whether the deal was a share sale or an asset sale.
What Changes for the Seller the Day After Closing
The moment closing happens, an individual seller has typically realized a capital gain or loss (if shares were sold personally) and a corporate seller has typically realized a gain or loss on the disposition of its assets (if it was an asset sale). Either way, that event needs to be reported — it doesn't just fold quietly into next year's numbers as if nothing happened. Only part of a capital gain is subject to tax, but the exact mechanics depend on current tax rules that can change, so this is squarely accountant territory rather than something to estimate yourself.
Filings an Individual Seller May Need to Address
- Personal income tax return reporting the capital gain, for the tax year in which the sale closed.
- A claim for the Lifetime Capital Gains Exemption (LCGE), if the sale involved qualifying small business corporation shares held personally. As of mid-2026, the exemption's base amount is roughly $1.25 million, indexed annually — confirm the current figure with your accountant before relying on it, since it changes over time and eligibility itself depends on a set of technical tests.
- Any instalment tax adjustments, since a large one-time gain can affect what instalments are required going forward.
Filings a Corporate Seller May Need to Address
- A corporate income tax return reporting the gain or loss on the assets sold, for the corporation's relevant taxation year.
- A GST/HST election filing, if the parties jointly elected under section 167 of the Excise Tax Act to have no GST/HST apply to a qualifying asset sale. If no such election was made, GST/HST generally applies to most taxable business assets — Ontario's HST rate is 13% as of mid-2026 (5% federal, 8% provincial), though this should be verified before relying on it for any filing.
- Wind-up or dissolution filings, if the corporation is being wound up after an asset sale rather than continuing to operate or hold the proceeds.
- Payroll and source deduction reconciliations, if employees were terminated or transferred as part of the sale.
Share Sale vs. Asset Sale: Who Files What
| Share Sale | Asset Sale | |
|---|---|---|
| Who realizes the taxable event? | The individual (or corporate) shareholder selling the shares | The corporation selling its assets |
| Common exemption in play | LCGE may shelter part of an individual's gain on qualifying shares | LCGE generally does not apply — it shelters share gains, not a corporation's own asset sale |
| GST/HST filing consideration | Share sales are generally an exempt supply — no GST/HST on the shares themselves | May require a section 167 election filing, or GST/HST collection and remittance if no election is made |
| What happens to the corporation afterward | It continues to exist, now under new ownership — no wind-up filing required for the seller | It may be wound up, sold as a shell, or retained to hold and later distribute the proceeds — each path has its own tax filings |
| Extraction of remaining funds | Not applicable — the seller already has the sale proceeds personally | If proceeds stay in the corporation, extracting them later (dividends, salary, wind-up) has its own separate tax consequences |
Why This Isn't a DIY Job
Capital gains treatment, LCGE eligibility, GST/HST elections, and corporate wind-up mechanics all interact with each other, and the rules governing each one change over time. A seller who assumes "my lawyer already handled the tax side during closing" is often mistaken — closing documents allocate purchase price and satisfy legal conditions, but the actual tax filings happen afterward, on the seller's own return, prepared with an accountant who can confirm the current rules apply the way you expect them to for your specific transaction.
Frequently asked questions
Do I need to file anything special if I sold my business through a share sale and claimed the Lifetime Capital Gains Exemption?
Yes — claiming the LCGE requires specific reporting on your personal tax return, and your accountant will need to confirm the shares actually met the qualifying tests at the relevant times. This isn't automatic just because the sale was a share sale.
What if my corporation is being wound up after an asset sale?
Winding up a corporation involves its own filings, separate from the tax return reporting the gain on the asset sale itself. Timing this properly with your accountant matters, since distributing remaining funds to shareholders has its own tax consequences.
Does the buyer or the seller file the GST/HST election if we agreed there'd be no GST/HST on the sale?
The election under section 167 of the Excise Tax Act is a joint election made by both parties, though the mechanics of who actually submits the form are typically coordinated between the parties' accountants as part of closing.
Can my lawyer file my post-closing tax returns for me?
No — your lawyer's role covers the legal documents and closing mechanics of the sale itself. The actual tax filings are your accountant's role, and the two professionals should be coordinating with each other well before closing, not scrambling afterward.
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