With one in three Canadian businesses planning acquisitions, HRFest Canada 2026 panellist discusses the integration traps that quietly destroy deal value
Most HR teams discover what they don’t know about mergers and acquisitions on the day the deal closes. At HRFest Canada 2026 on Nov. 10 and 11, that’s precisely the knowledge gap Karin Adams, Vice President of Talent and Total Rewards at TMX Group in Toronto, intends to address.
One in three Canadian business leaders are planning major mergers and acquisitions (M&A) in the next 18 months, according to a January 2026 KPMG Canada survey of 252 business leaders across 14 sectors. Canada’s nation-building agenda and steady interest rates have created a favourable dealmaking environment – and a growing urgency for HR professionals to understand what they will face when those deals arrive.
Adams is one of the panellists in “Deals and People: The M&A Landmines That Take HR Down,” a 20-minute session covering the foundations HR leaders often discover too late: share and asset deal mechanics, how to retain the key talent that makes an integration work, how to manage employees on leave when ownership changes, and how to communicate through a process where much cannot yet be disclosed.
The hidden costs business leaders miss
Among the most persistent misconceptions Adams says she encounters is the belief that the cost of an acquired company is essentially fixed at close.
“There’s often significant, what I’d call hidden integration or harmonization costs,” says Adams. “A lot of times business leaders can think we’re just buying the company as it is and we can keep operating it at their current cost base, but the reality is there’s often a lot of hidden HR costs, program costs, and integration and harmonization costs that ultimately impact deal value.”
Benefits alignment, compensation restructuring, and HR systems integration rarely appear in the original deal model – unless HR has raised them early enough in diligence to be incorporated, according to Adams.
“It becomes critical for HR leaders to raise those early in the diligence process so they can be modeled into the overall deal value and ultimately be a potential decision-maker for whether the deal proceeds or not,” she says.
As HRD Canada has reported on Canada’s accelerating M&A activity, those people costs are significant. Mercer’s research report “Bridging Uncertainty: How Strategic Retention Drives M&A Outcomes” found that approximately 40 per cent of critical talent is lost in the 18 to 24 months following a transaction. A related study by the Transaction Advisors Institute, produced with Mercer in 2025, found that 95 per cent of corporate acquirers say they assess human capital before a deal in some form, yet only 41 per cent actually apply it when formulating the deal thesis.
Culture and the leadership question
Hidden costs can be modelled. Culture cannot – and Adams considers it the variable most consistently underestimated in M&A planning.
“I still think it’s sometimes underestimated, the impact that competing cultures can have on the success of a deal and a subsequent integration, as well as leadership issues,” says Adams. “I think it takes a lot of candour in these deals to be realistic about what your state looks like, and then have really honest and transparent conversations with the leadership team you’re acquiring on what their hopes, wishes, and dreams are.”
When that candour is absent and leadership expectations diverge, the consequences follow a predictable pattern: “A lot of times that gets missed, and that’s ultimately when the talent leaves the door,” says Adams. “Then you don’t have the deal proposition that you thought you did.”
Getting day one right
The third landmine Adams identifies is what she calls a “Goldilocks” problem: over-preparing for day one carries as much risk as under-preparing.
“Oftentimes, if you’re spending too much time making the big decisions before day one, you’re missing the opportunity to learn about the culture and the organization and hear more post-close from the company you’re acquiring,” she says. “Similarly, you can underprepare, and if you don’t provide some sense of certainty around key questions and critical milestones for day one, it can breed a lot of fear and uncertainty and, again, cause some cultural and talent disruption that will impede your objectives.”
The quality and timing of decisions matter as much as the decisions themselves – a judgment that only develops with early enough involvement, says Adams.
Making the financial case for a seat at the deal table
At TMX Group, early HR involvement in deals is already the expectation, not a concession, according to Adams.
“I ultimately think the earlier we’re involved, the more likely the business is to achieve success,” she says. “Certainly at TMX Group, HR is a trusted partner in the deal process. We’re brought in quite early. If you’re brought in on day 1, it’s far too late.”
HRD Canada has explored how transformation is reshaping people strategy across Canada’s organizations – and M&A integration is one of the highest-stakes environments where that shift is tested. Where HR’s standing at the deal table is still being established, Adams points to a direct route in: the financial model.
“If you’re an HR leader who is struggling to find your seat at that table in a deal, I think reminding about the financial impact of some of the people costs – which in many deals is quite significant and impacts the returns and what you’re hoping to do,” she says. “Having someone who can draw your pencil on the actual financial model of the deal with some of the biggest cost drivers is why you want them at the table.”
That reframing – from HR as program manager to HR as financial stakeholder – is one of the more portable arguments a practitioner can make when influence still has to be earned in the deal room, and one Adams hopes to include in her session at HRFest Canada 2026.
Uniting HR leadership community
With more than 750 HR leaders expected at HRFest Canada 2026 on Nov. 10 and 11, Adams sees the conference’s value as much in the community it assembles as the content it delivers.
“I feel like with any HR community event, the takeaway is this sense that they’re not alone and that whatever issues they experience in M&A, there’s probably a peer out there who has also experienced it,” she says. “It’s a shared experience across HR leaders, particularly over the past few years, that really unites us – and so whether it's to see people that you have crossed paths with before or to create a new peer, get some new ideas and thought leadership, that's what going to these sessions really are about.”
