Air Canada’s (TSX: AC) C$800 million substantial issuer bid closed at C$29.00 per share, the bottom of its C$29–C$33 Dutch-auction range. The airline purchased 27,586,206 shares, representing about 9.8% of its shares outstanding before the offer, and ordinary qualifying tenders were subject to approximately 41% proration. Holders of qualifying odd lots were exempt from that reduction.
For our 99-share paper trade, that sounds like a successful result. We recorded a C$28.13 reference price on September 9, when the tender was still open, which makes the final C$29.00 payment a C$86.13 gross profit, or 3.1%, on C$2,784.87 of hypothetical capital. Unfortunately, Air Canada has now also supplied the number that makes the after-withholding calculation far less appealing: an estimated C$18.40 deemed dividend on each tendered share.
The odd-lot preference worked
In our September odd-lot paper portfolio, we used the closing price available before the outcome was known and committed to reporting the results later. We did not buy Air Canada shares for that portfolio; these are hypothetical trade figures, before commissions, currency conversion, brokerage corporate-action charges or taxes. The reference price was C$28.13 and the assumed position was 99 shares.
| 99-share paper position | Result (C$) |
|---|---|
| Reference purchase price | 28.13 per share |
| Initial cost | 2,784.87 |
| Final tender price | 29.00 per share |
| Gross tender proceeds | 2,871.00 |
| Gross profit | 86.13 |
| Gross return | 3.09% |
Air Canada’s September 28 final results confirm that the airline took up and paid for the shares at C$29.00 and that approximately 41% of ordinary eligible tenders were accepted, excluding odd lots. The roughly 59% of eligible ordinary tenders left unaccepted illustrates the economic value of being exempt from proration. For a properly tendered 99-share position meeting the odd-lot conditions, the entire position could be purchased at the clearing price.
It was still a floor-price outcome, much as we anticipated in September. Air Canada’s 2025 substantial issuer bid also cleared near the bottom of its auction range, and this one attracted far more shares than the company planned to repurchase. The upper end of a Dutch-auction range was never a promised sale price.
The C$18.40 deemed dividend changes the cash calculation
When a Canadian corporation buys back its own shares, Canadian tax rules can treat the amount paid above a share’s tax paid-up capital as a dividend. Air Canada estimates its paid-up capital at C$10.60 per share, so its C$29.00 tender generated an estimated C$18.40 deemed dividend per share. For 99 shares, that is C$1,821.60 of deemed dividend income even though the gross profit above our reference purchase price was only C$86.13.
Canadian nonresident dividend withholding generally starts at 25%, but an eligible U.S. beneficial owner can qualify for a 15% treaty rate. The Canada–U.S. tax treaty provides that reduced rate for ordinary individual dividend recipients who meet its conditions. Whether the correct rate is applied in a particular brokerage account depends on documentation, beneficial ownership, treaty eligibility and intermediary processing.
| 99 shares, modeled cash received | No withholding | 15% withholding | 25% withholding |
|---|---|---|---|
| Gross tender proceeds (C$) | 2,871.00 | 2,871.00 | 2,871.00 |
| Withholding on C$1,821.60 deemed dividend | 0.00 | 273.24 | 455.40 |
| Cash after withholding (C$) | 2,871.00 | 2,597.76 | 2,415.60 |
| Cash less C$2,784.87 reference cost | +86.13 | −187.11 | −369.27 |
These are withholding scenarios, not actual statements from a brokerage account. At 15%, the C$273.24 modeled deduction is more than three times the C$86.13 gross trading profit. At 25%, the deduction would be C$455.40, a particularly bad outcome for anyone who had counted on the odd-lot preference to produce a quick cash gain.
Withholding is not necessarily the final tax cost
A U.S. taxpayer might be eligible for foreign-tax-credit relief or other adjustments, but the amount withheld is not automatically refundable or creditable in full. U.S. tax treatment of the share redemption, applicable holding periods, foreign-source-income limits and the investor’s circumstances can affect the outcome. The IRS guidance on foreign tax credits sets out limitations that are especially relevant to short-term trades, and the Canada Revenue Agency requires sufficient information to establish treaty eligibility.
Consequently, the C$187.11 figure is a modeled cash shortfall after 15% withholding, not a verified final after-tax investment loss. Nor does the original C$86.13 gross profit tell the whole story for a U.S. shareholder. Someone considering this sort of transaction would have needed to understand the deemed-dividend mechanics and their own broker’s treatment before tendering.
Compare this with our Arbutus postmortem: that odd-lot preference also worked, but the paper trade lost 3.3% because the auction cleared below our reference purchase price. Air Canada cleared above our reference price and accepted qualifying odd lots in full. Its potential failure point was the tax treatment of the proceeds, not the auction or proration mechanics.
Our odd-lot tender explainer covers why a 99-share position sometimes has advantages over a 100-share one. Air Canada’s completed offer demonstrates the limit of that advantage: preferential acceptance guarantees neither an attractive clearing price nor attractive net cash proceeds. The original paper-trade scorecard gets a +C$86.13 gross entry, accompanied by a prominent Canadian-withholding warning rather than a claim of realized profit.