An assignment sale looks, from the outside, like an ordinary resale with an extra step. It isn’t. The assignee is buying rights under someone else’s contract with the builder, not the unit itself; the builder usually has to consent; and the tax question that follows — whether HST applies to the assignor’s profit — turns on facts that have nothing to do with the numbers on the agreement.
Key takeaways
An assignment sale is the original purchaser of a pre-construction unit — the assignor — transferring their rights under the purchase agreement to a new buyer, the assignee, before the building has registered. As Treadstone Law’s guidance puts it plainly, “there’s no title to transfer yet — the assignee is buying a contractual position, not the unit itself, and eventually takes title from the builder once the building is ready.” That distinction matters practically: the assignee’s deal is with the assignor for the contractual rights, and separately with the builder for the eventual conveyance of title — two different relationships, not one simple resale.
Most original purchase agreements address assignment directly, and few permit it freely. Some prohibit it outright; others require the builder’s written consent, often with a consent fee paid by the assignor. (Treadstone Law, Assignment Sales & Title Ownership) Whether the builder can withhold consent, and on what terms, depends entirely on the specific clause — reading it before advertising a unit for assignment, or before advising a client to buy one, is the first step on either side of the deal, not a formality to check after a price is agreed.
When a buyer purchases a pre-construction unit directly from a builder, HST on the purchase price is straightforward. An assignment adds a second, separate transaction — the assignor is selling contractual rights, not the unit — and the Excise Tax Act treats it differently depending on facts specific to the assignor. Where the assignor signed the original contract with no intention of living in or renting the unit, and always meant to resell before closing, CRA’s position is that this is an adventure in the nature of trade — a business activity — and the assignment fee, the profit above the original deposit and any upgrades, is taxable, with the current combined federal-and-Ontario HST rate applying to it. Because the assignor was never acquiring the unit for personal use in this scenario, they also don’t qualify for the new housing rebate on the unit itself. (Treadstone Law, HST on Condo Assignment Sales in Ontario)
Where the assignor genuinely intended to occupy the unit as a primary residence when they signed, and circumstances changed — a job relocation, a growing family, financial hardship — there’s an argument the assignment fee isn’t subject to HST at all, because the assignor wasn’t acting in a commercial capacity. But the outcome isn’t guaranteed: CRA and the courts look at the full picture — what the assignor told the builder at signing, whether they arranged end-user financing, whether they applied for the new housing rebate, and whether their conduct is otherwise consistent with genuine personal-use intent. (Treadstone Law, HST on Condo Assignment Sales in Ontario) Treadstone Law’s own assignment guidance is candid that this area is genuinely complex and that “getting it wrong is one of the costliest mistakes an assignor can make” — there is no shortcut version of this rule safe to repeat to a client either way.
The Excise Tax Act places obligations on both builders and assignors, and this is where deals go sideways. Where the builder is party to the assignment — as many are required to be under the original purchase agreement — the builder may be positioned to collect HST on the assignment fee and remit it. But builders often disclaim responsibility for the assignor’s HST, leaving that obligation with the assignor; if HST applies and the assignor isn’t registered for HST, they may still have to remit on a self-assessment basis, and the assignee can face a self-assessment obligation in some circumstances if the assignor didn’t collect. (Treadstone Law, HST on Condo Assignment Sales in Ontario) Both sides can end up assuming the other handled it, and neither did. The safest practice is addressing HST explicitly in the assignment agreement itself, confirming the assignor’s registration status, and getting written confirmation from the builder about its role.
The assignee’s own entitlement to the new housing rebate on the unit itself flows from the builder’s sale to the original purchaser, not from the assignment transaction — it’s unaffected by whether the assignor’s own assignment fee attracted HST. (Treadstone Law, HST on Condo Assignment Sales in Ontario) The assignee also steps into the assignor’s original deposit position with the builder, which carries its own protection: pre-construction deposits are subject to Ontario’s deposit protection regime, with Tarion providing coverage up to a statutory limit that depends on when the original agreement was signed — amounts above that limit need to be separately secured, typically through a letter of credit or insurance bond specified in the agreement. See warranty coverage a new home buyer gets for how that same statutory framework carries through once the assignee closes and takes possession.
A client signed a pre-construction agreement 18 months ago genuinely intending to live in the unit, then received a job offer in another city and needs to exit before the building registers. They find a buyer willing to pay $60,000 above their original price plus upgrades. Before setting that number, three things need confirming: whether the builder’s agreement permits assignment at all, and on what consent terms; whether the client’s documented circumstances — the job offer, any change-of-plans correspondence with the builder — genuinely support the personal-use HST position rather than assuming it applies by default; and who, in writing, is responsible for HST if it does apply. None of the three is optional, and skipping any of them is how an assignor ends up with an unexpected tax bill months after the deal has already closed. See small commercial deals you can take on for the same underlying discipline — recognizing when a transaction needs specialist tax or legal input before a price gets set, not after.
Yes, if the original purchase agreement prohibits it outright — per Treadstone Law’s guidance, very few builder agreements permit assignment freely, and the specific clause controls whether consent is available at all, and on what terms.
No, and treating it as a fixed rule is the mistake. Treadstone Law’s HST guidance is explicit that the outcome depends on the assignor’s original intent and the full fact pattern — confirm the specific situation rather than assuming either answer.
It’s worth confirming independently. Treadstone Law’s guidance notes the assignee can face a self-assessment obligation in some circumstances if the assignor didn’t collect HST that was actually owing — a written, confirmed position in the assignment agreement protects both sides.
A short call can help identify what documentation actually supports a client’s position before a price is set.
