Can I use multiple family holding companies to multiply the capital gains exemption on one sale?

In principle, yes — if multiple family members each genuinely hold qualifying shares in their own right, whether directly, through their own holding companies, or as real beneficiaries of a family trust that allocates the gain to them, each of those individuals has their own separate exemption to apply against their own share of the overall gain. Structuring ownership this way so that more than one family member's exemption is available on a single sale is often called "multiplying" the exemption, and it's a legitimate, well-established planning technique when done properly.

The key word is properly: this needs genuine, bona fide ownership reflecting real economic interests set up well in advance, not nominal shareholders inserted shortly before a sale purely to claim exemptions they have no real stake in. The CRA scrutinizes multiplication arrangements closely for exactly this reason, and structures that look artificial, or that were implemented too close to a sale without real substance behind them, risk being challenged under anti-avoidance rules.

Because doing this correctly takes real lead time, careful documentation, and coordination between family members' own tax situations, this is planning to build years ahead of a sale with a tax advisor, not something to attempt once a buyer is already at the table.