Can I insist part of the price be held back just to cover a possible CRA reassessment?

Yes, and this is a common and sensible request in a business purchase and sale where the buyer is worried about pre-closing tax exposure. There is no legal requirement for a tax-specific holdback, so whether a seller agrees depends entirely on negotiation, but tying a holdback to a known or suspected tax risk is a well-recognized way to allocate that particular concern without capping or complicating the rest of the indemnity structure.

A tax-specific holdback is usually paired with a tax indemnity that lets the buyer draw on the held-back funds if the Canada Revenue Agency actually reassesses the corporation for a pre-closing period, rather than leaving the buyer to pursue the seller directly after the money has already been paid out. The amount held back and the length of time it is retained are negotiated based on how real the CRA risk appears to be, often informed by the corporation's own tax filing history and any known outstanding issues. Structuring this correctly, including how and when the holdback is released if no reassessment occurs, is worth working through with a Treadstone business lawyer.