Notifying the CRA of a Change in Business Ownership in Ontario

Buying or selling a business changes more than who signs the lease. It also changes who the Canada Revenue Agency thinks it's dealing with — and if nobody updates the CRA's records, you can end up with mail, remittances, and notices of assessment going to the wrong person at exactly the moment you can least afford confusion.

The good news is that notifying the CRA of a change in business ownership is largely administrative, not legally complicated. But which accounts need to move, close, or open depends entirely on how the deal was structured. A share sale and an asset sale trigger very different CRA housekeeping.

This article walks through what typically needs attention on the CRA side after an Ontario business changes hands, so nothing falls through the cracks in the weeks after closing.

Why the CRA Process Depends on Deal Structure

Every Ontario business dealing with the CRA has a Business Number (BN), with program accounts hanging off it for things like corporate income tax, GST/HST, and payroll deductions.

• In a share sale, the corporation itself doesn't change — the same legal entity keeps its BN and program accounts. What changes is who controls it.
• In an asset sale, the buyer is usually a different legal entity altogether. The seller's BN and accounts stay with the seller; the buyer generally needs its own BN and its own program accounts.

Get this distinction wrong and you can end up either registering accounts you don't need, or failing to register ones you do.

If You Bought or Sold Shares

Because the corporation continues, most CRA account numbers don't change. What typically does need updating:

• Directors and officers on file. The CRA's corporate records should reflect the new board and signing officers, particularly for anyone who will deal with the CRA on the corporation's behalf.
• Authorized representatives. Whoever previously had online access to the corporation's CRA accounts (through My Business Account or Represent a Client) should be removed, and the new owner's advisors added, so the incoming owner isn't locked out of its own tax accounts.
• Mailing address and contact information, if the business is relocating or the new owner wants correspondence sent elsewhere.
• Outstanding tax matters. Buyers in a share deal inherit the corporation's tax history, including any open audits, unfiled returns, or amounts owing — this is exactly why tax due diligence and representations/warranties about tax compliance matter so much in a share purchase agreement.

If You Bought or Sold Assets

Because an asset sale usually involves two separate legal entities, the CRA housekeeping runs in both directions:

For the buyer:

• Register a new BN if the buyer doesn't already have one.
• Open the program accounts the new operation actually needs — typically a GST/HST account if the business will be making taxable supplies, and a payroll account if it will have employees.
• Confirm the corporate income tax account is set up correctly if the buyer is operating through a corporation.

For the seller (where the business isn't continuing under the seller's entity):

• Wind down or close program accounts that are no longer needed once outstanding returns and remittances are filed.
• Keep records available, since the CRA can still review prior periods after the accounts are closed.

The GST/HST Question

GST/HST generally applies to the sale of most business assets. In Ontario that means HST — currently 13% as of mid-2026, though you should always verify the current rate before closing, since rates and rules can change.

On a qualifying asset sale, the buyer and seller can jointly elect under the Excise Tax Act to have no GST/HST apply to the transaction, where the buyer is acquiring all or substantially all of the property needed to carry on the business. Whether your deal qualifies is a fact-specific question your lawyer and accountant should work through together — our tax law team regularly helps structure this alongside the sale itself, since getting it wrong can leave either side on the hook for tax that should have been collected, or wasn't.

A share sale is treated differently: the sale of shares themselves is generally exempt from GST/HST, regardless of what the underlying corporation owns.

A Practical CRA Checklist After Closing

• [ ] Confirm whether the deal was a share sale or asset sale, and identify which CRA accounts actually need to change.
• [ ] For a share sale: update directors, officers, and authorized representatives on the corporation's CRA accounts.
• [ ] For an asset sale (buyer): register a new Business Number and the program accounts the business needs.
• [ ] For an asset sale (seller): file final returns and close program accounts once they're no longer needed.
• [ ] Confirm whether a GST/HST election applies to the transaction, and document it properly if so.
• [ ] Update the mailing address and preferred contact method on file with the CRA.
• [ ] Ask your accountant to confirm nothing else — payroll remittances, instalments, prior-year filings — is left outstanding on either side of the deal.

Frequently asked questions