The Law Firm Merger Wave

What It Actually Means for Your Career If You’re at One of These Firms

I’ve been working in City legal recruitment for long enough to have seen several waves of merger activity, each of which was described at the time as transformational. Some were but most were not. What has happened in the London legal market over the last two years is genuinely different-in pace, in scale, and in what it means for the lawyers caught in the middle of it.

In under twenty-four months, the City has seen A&O Shearman launch (Allen & Overy + Shearman & Sterling, May 2024), HSF Kramer go live (Herbert Smith Freehills + Kramer Levin, June 2025), Ashurst Perkins Coie announced (November 2025, completing Q3 2026), Winston Taylor approved (Winston & Strawn + Taylor Wessing, launching May 2026), and Hogan Lovells + Cadwalader announced-which at 3,100 lawyers and $3.6 billion in combined revenue would be the largest transatlantic law firm combination ever attempted. According to Fairfax Associates, 47 law firm mergers completed in the first three quarters of 2025 alone, up from 43 in the whole of 2024. Law firm mergers rose 25% to a record 59 deals across 2025 in total.

Most coverage of these deals focuses on the strategy: the revenue rationale, the geographic ambition, the leadership structure, the combined headcount. All of that matters but none of it is what the partners and senior associates calling me are asking about. What they want to know is simple: what does this actually mean for me?

The Wave at a Glance

Before getting into the human impact, here is the full picture of where things stand. This is the most concentrated period of transatlantic law firm combination activity in the history of the profession.

Sources: Bloomberg Law; Global Legal Post; Legal Cheek; Above the Law; Attorney at Law Magazine. Data correct as of May 2026.

Each of these combinations is driven by a version of the same strategic logic: UK firms need genuine scale in the US to compete for the cross-border mandates that increasingly define the premium end of the global legal market. US firms want a credible international footprint and access to UK and European client relationships. As one legal commentator put it: “For law firms that aspire to global market leadership, the US is an imperative.”

The driver behind the wave is also competitive pressure from a specific source. Kirkland & Ellis, Latham & Watkins, Paul Weiss, and other elite US firms have spent a decade building London practices that now generate revenues larger than many established City firms. They have systematically attracted the best partners and most profitable practice areas. The UK firms that are now merging are not responding from a position of strength-they are responding because the alternative, standing still, is no longer viable.

What History Shows Happens After These Mergers

The press release always describes the merger as a combination of equals, united by complementary strengths, shared values, and a bold vision for the future. Sometimes that is exactly what happens and sometimes not. The pattern of what actually follows a major law firm merger is well-documented, and lawyers at these firms deserve to understand it clearly.

Partner departures aren't an abstract concept, they're almost certain.

Every major law firm merger produces partner departures. The only questions are how many, from which practice groups, and how quickly. When HSF merged with Australian firm Freehills in 2012-a deal now considered a success - “a large number of London-based partners left the firm in the immediate aftermath.” That is a direct quote from how the firm itself now describes the period. The merger was right strategically but the execution was painful for many individuals caught in the transition.

Kramer Levin’s Paris office-sixty lawyers, the firm’s only non-US base-was not included in the HSF merger and was spun out to Morgan Lewis before the deal completed. Sixty lawyers, left to find a new home, because they didn’t fit the strategic picture of the combined entity. This is not unusual. 

Departures happen for several reasons, some partners see the cultural shift coming and pre-empt it, some lose internal battles about practice group leadership in the new structure and some find that their client relationships, which were central to their position at the legacy firm, are now seen as duplicative or conflicted by the merged entity’s existing client base and some simply don’t want to work in the firm that emerges.

Integration takes longer and costs more than projected.

A&O Shearman launched in May 2024. It is now entering its third year of integration. The strategic rationale was clear. The execution-aligning two firms with different compensation structures, different billing cultures, different approaches to associate development, and different client expectations-is a multi-year project. Associates at A&O Shearman today are working inside a firm that is still actively integrating. That creates opportunity for some but for others, it creates noise, uncertainty, and a distraction from the work they came to do.

The leadership structure matters more than it looks in the press release.

HSF Kramer’s leadership team has five of its six executive partners from legacy HSF. In a “merger of equals,” that is not equality. It is acquisition with better PR. Lawyers at legacy Kramer Levin knew this going in-the deal was clearly a strategic necessity for the US firm to gain international scale. For the lawyers at Kramer, the question was whether they trusted the HSF leadership to deliver on the promised opportunity. Those that didn't made their move before or shortly after launch.

When A&O merged with Shearman, legacy Allen & Overy had 100 trainees in London. Legacy Shearman had around 15. The combined firm’s identity and culture will inevitably be shaped by which legacy is the dominant one. At Ashurst Perkins Coie, the co-CEO structure with Ashurst’s Paul Jenkins and Perkins Coie’s Bill Malley is presented as genuinely equal. Whether that holds through the integration, when the harder decisions about practice group leadership and compensation structures are made, will be the real test.

The Culture Clash Nobody Warns You About

This is the section I most want lawyers at these firms to read carefully, because it is the thing that creates the most displacement-and that is most consistently underestimated when merger deals are announced.

UK and US law firm partnership models are genuinely different in ways that matter profoundly to how you practise law and how you are compensated. When two firms with different models combine, one model wins. That transition produces winners and losers at the individual lawyer level. Understanding which model will predominate in the merged entity-and whether that model suits you-is the most important career question a lawyer at one of these firms needs to answer.

Bloomberg Law put this directly: 

“One aspect of the mergers that has led to some partner departures is the cultural change to partnerships when a firm adopts the US model.” 

That is a careful diplomatic framing of something more specific: some UK partners, often very good ones, find that they are not suited to an origination-first, performance-linked environment where feeding yourself is the baseline expectation from day one of partnership. It is not a question of ability but of fit.

For associates, the culture shift manifests differently. US-model firms tend to run leaner teams, with higher individual output expectations and less of the structured support layer that UK Magic Circle and Silver Circle firms provide. The billing expectation and availability culture are significant. The upside is that so are higher compensation, faster responsibility and clearer meritocracy. The question for a legal associate at a newly merged firm is: which side of that trade-off am I getting?

If You’re a Partner at One of These Law Firms

The conversations I have most often at the moment are with partners at A&O Shearman, HSF Kramer, and-increasingly, even before the deal closes-Ashurst who are trying to make sense of their position in the new structure.

The most important thing I tell them is this: the best time to assess your options is now, not after the integration shakes out. The partners who wait to see how the dust settles often find that by the time the picture is clear, the most attractive lateral opportunities have been filled by colleagues who moved earlier. The City lateral partner market is active-legal lateral hiring surged 9% to over 28,000 hires in 2025, with Am Law 50 firms capturing an increasing share of the best talent. That market will not wait indefinitely for one individual to make a decision.

The specific questions a partner at a merged firm should be asking:

Practice group leadership: who is heading my practice area in the combined structure? Is it someone from my legacy firm, or from the other side? What does that mean for my access to the best matters, the best teams, and the internal visibility that drives compensation in a merit-based system?

Client conflicts: are any of my most important client relationships now potentially conflicted by the other firm’s existing client base? If so, how is that being managed? Client conflicts in merged firms are rarely discussed openly in the announcement period, but they are one of the most common reasons partners leave post-merger.

Compensation transition: how is the combined firm handling the shift between the two legacy compensation structures? Is there a protected period? What are the performance metrics in the new system, and how am I positioned against them?

The origination question: in the merged firm, how much of the work flowing through your practice area can genuinely be attributed to your relationships versus the firm’s institutional client base? If the answer is ‘mostly institutional,’ you need to think carefully about whether you have the book of business to thrive in a more performance-linked environment.

The partners who move best move from a position of choice. Those who wait until the picture is uncomfortable often find the best opportunities have already gone.” 

Sean Nicholson, Managing Director-City Desk

I am not suggesting that every partner at a merged firm should leave. Many will find that the combination genuinely enhances their practice-the cross-border deal flow, the US client access, the broader platform. A&O Shearman, for those whose practice benefits from genuine transatlantic connectivity, is a more powerful platform than either legacy firm was alone. The same will be true for HSF Kramer and, potentially, for Ashurst Perkins Coie but ‘the combined firm is better’ is a strategic statement. Whether it is better for you, specifically, is a different question.

If You’re a Senior or Mid-Level Associate

For associates at merged firms, the immediate picture is often more stable than for partners. Your day-to-day work, your supervisor, and your deal flow are unlikely to change dramatically in the first year of a merger but the medium-term picture is what matters, and that is where the questions need to be asked.

The compensation trajectory

One of the structural effects of UK-US mergers is upward pressure on associate compensation at the merged entity. When A&O Shearman formed, the expectation of US-market-level rates-and the competitive pressure to retain the best associates-pushed the combined firm’s pay structure upward. Ashurst, separately, boosted its NQ salary by £15,000 in 2025 as it prepared for its Perkins Coie combination. Associates at these firms, if they stay, will generally benefit from this pressure. The merged platforms need strong associate talent and the financial firepower to attract it.

The partnership track

This is where the picture is most complex, and where I see the most uncertainty among mid-level associates at merged firms. A merger does not widen the partnership funnel-in the short to medium term, it typically narrows it. The combined firm has more senior lawyers competing for the same number of partnership promotions. Internal rivalry between legacy cohorts for the best matters and the best relationships can be intense and the criteria for partnership in the merged entity-increasingly origination-weighted, increasingly US-influenced-may be different from what associates at the UK legacy firm had been preparing for.

If you are a 4–6 PQE associate at A&O Shearman, HSF Kramer, or Ashurst Perkins Coie, you need to understand clearly whether the partnership track you were on at the legacy firm still exists in the same form in the new structure. In many cases it does, and the merged platform genuinely enhances it. In some cases it doesn’t, and the honest answer is that the competition just got harder.

The market opportunity

Here is what merger activity at these firms creates, consistently: lateral opportunity elsewhere. When partners leave merged firms, they take teams, open new positions, and create demand for strong associates at the firms they join. When practice group leadership shifts, capable lawyers who feel undervalued or overlooked in the new structure become available to the market. The most active lateral hiring moment at any firm is the twelve to twenty-four months immediately after a major merger. For associates at unaffected firms, this is the window to move into spaces opened by that displacement.

The Firms Not Merging-And What That Signals

The merger wave has a counternarrative that deserves equal attention: the firms that are choosing not to participate, and what that deliberate choice means for the lawyers who work there and those considering joining them.

Freshfields: the organic play

Freshfields has made the most aggressive organic bet of any Magic Circle firm. It has opened four US offices-including a Boston office in early 2025-and reported a 26% increase in US fee income, contributing to total revenue of £2.1 billion. It has started resisting the ‘Magic Circle’ label, repositioning as a global elite firm competing directly with the US market rather than seeking a merger partner to get there. This is a high-conviction strategic call. If it works, Freshfields emerges with its culture intact and its profits undiluted. If the US build-out stalls, the pressure to find a partner will intensify.

Slaughter and May: the deliberate exception

Slaughter and May’s position is not stasis-it is a deliberate strategic choice. The firm advises more FTSE 100 companies than any other, operates a ‘best friends’ model for international work, has no formal billing targets, and has a profit per equity partner that remains among the strongest in the UK market. Slaughters has watched multiple rounds of merger activity from a position of considered non-participation. Its lawyers are not stuck-they are at a firm that has chosen a specific identity and committed to it. For lawyers who want that environment, the merger wave is actually an argument for Slaughters, not against it.

Linklaters and Clifford Chance: watching, for now

Neither Linklaters nor Clifford Chance has announced a merger partner. Both are watching the integrations of their peers with interest. Linklaters reported a 24% increase in US turnover and £2.1 billion in total revenue for 2024. Clifford Chance continues to expand its US operations. Neither is under immediate pressure to merge but the competitive logic that drove A&O, HSF, and Ashurst to the merger table has not disappeared. The question for lawyers at these firms is when will they be faced with the same pressure?

What I’m Seeing from the City Desk Right Now

Speaking plainly about what we are seeing at JMC’s City desk, because it is more useful than a general assessment.

Partner movement is elevated. The number of partners in active conversation about their options has increased significantly since late 2025. Not all of them will move but the number who are seriously weighing their position-rather than assuming continuity-is the highest I’ve seen. The firms they are most interested in are the stronger US platforms with established London practices (Latham, Paul Hastings, Milbank, Davis Polk), the firms going it alone with strong organic momentum (Freshfields, Macfarlanes), and in some cases boutique or emerging practices where their client relationships can be the centre of the firm rather than one part of a large platform.

Mid-level associates are reassessing. The 4–6 PQE window, which is always the most active for lateral movement, has become more turbulent at the merged firms. Associates who were comfortable with their partnership trajectory are being asked to re-examine that trajectory in a new structure, often without fully clear answers from the firm’s leadership. Some are using that uncertainty productively-assessing the market, understanding their options, and making deliberate decisions. Others are waiting, which is rarely the right call.

The firms not merging are becoming more attractive to some. I am having more conversations with lawyers who are specifically interested in Slaughter and May, Macfarlanes, and the Silver Circle firms for reasons of culture and stability, not just compensation. The merger wave has reminded some lawyers what they actually value in a firm.

The One Thing I’d Say to Every Lawyer at a Merged Firm

The merger wave is not going to stop. The strategic logic is not going away, if anything, the firms that have not yet merged will face increasing pressure to do so as the gap between the transatlantic platforms and the purely domestic or regional practices widens.

For lawyers inside these firms, the message is simple: this is the moment to be clear-eyed about your position, not reactive and panicked. Is the firm that emerges from this merger one where your practice genuinely thrives? Is the partnership track you were on still intact in the combined structure? Is the culture that made you join the legacy firm still the dominant one? If the answers are yes, stay and lean in. The merged platforms, done well, are genuinely powerful places to build a career.

If the answers are uncertain-or if you know, privately, that the answers are no-then the time to understand your options is now, before the merger settles and the market moves on. The most active, most well-positioned window for lateral movement is always in the period of integration. That window does not stay open indefinitely.

My door is open for that conversation. There is no obligation and nothing on the table until you want there to be, just an honest view of the market from someone who lives in it every day.

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