Market intelligence · Partner economics
Partner Book of Business by Legal Market
Across more than 2,600 partner-level conversations in our interview corpus, books cluster in the USD 2–5 million band across London, New York, and Paris — but that range conceals more than it reveals. What actually determines whether a book moves with the partner is portability, not size, and portability varies systematically by market, practice, and firm tier. London and New York show the highest low-portability rates of any major markets in our data (20% and 21% of assessed conversations respectively). Paris shows the tightest distribution and lowest low-portability share (10%). Gulf markets skew strongly portable — but not universally so.
‘How big is your book?’ is the wrong first question.
Pick a market. The median barely moves — but the share of books that will not survive the move swings by 2x.
Share of assessed London partners whose book is classified as low portability — roughly one in five, the highest-institutional major market in our data. Sartori & Partners corpus — nA=163 assessed
Same job title, same modal book size, double the lock-in risk depending on the market. Size is what partners report; portability is what recruiters diligence. The dataset behind every figure is described below.
What does a partner book of business actually look like by market?
In our interviews with 2,600+ partners, the modal answer to 'how big is your book?' is somewhere in the USD 2–5 million band. But that modal answer obscures four things that matter more than the number itself.
- 2,667+
- Partner-level conversations in Sartori Global's proprietary interview corpus — the dataset behind every figure on this page.
- Sartori Global research desk, 2026
- ~£2m
- Median GBP-denominated book for London partners in our corpus. USD-denominated London books (US firms) cluster near $3.5m median.
- Sartori Global interview corpus — banded aggregate, n=112
- ~€2m
- Median EUR-denominated book for Paris partners across 46 conversations — tighter distribution than London or New York.
- Sartori Global interview corpus — banded aggregate, n=46
- ~20%
- Share of assessed London partners carrying books classified as low portability — among the 163 London conversations where portability was assessed (assessed basis; excludes not-assessed).
- Sartori Global interview corpus — banded aggregate, nA=163 assessed
In our interviews with more than 2,600 partner-level candidates, reported books cluster in the USD 2–5 million band across London, New York, and Paris. Median GBP-denominated books in London land around £2 million. Median USD-denominated books in New York sit near $2.5 million. Paris EUR-denominated medians are close to €2 million. Emerging Gulf market books (Dubai, Abu Dhabi, Riyadh) are similarly sized in absolute terms but with a very different portability profile. The range in the largest USD-denominated markets (London, New York) runs from under $1 million to above $30 million; in Paris the EUR upper end is around €4.5 million and in Dubai the USD upper end is around $7.5 million. The median is not a floor and it is not a ceiling.
Four things matter more than the headline number. First, currency is not cross-converted in this analysis: a £2 million London book is not the same economic object as a $2 million New York book even at current exchange rates, because the rate structures, client expectations, and partnership profit models behind each are different. Second, portability determines whether the book actually moves with the partner, and portability varies sharply by market, practice, and firm tier — a large book with low portability is worth considerably less to a recruiting firm than a smaller highly portable book. Third, the corpus skews toward active or open-to-move candidates at international, US, and Magic Circle firms — it does not represent the full partner population and readers should not over-generalise. Fourth, the firm-side threshold for what counts as an acceptable book varies enormously by firm and is not captured here.
It hides currency
Currency is not cross-converted here. A £2m London book is not the same economic object as a $2m New York book even at current rates — the rate structures, client expectations, and profit models behind each are different.
It hides portability
Portability determines whether the book actually moves with the partner, and it varies sharply by market, practice, and firm tier. A large book with low portability is worth less to a recruiting firm than a smaller, highly portable one.
It hides survivorship
The corpus skews toward active or open-to-move candidates at international, US, and Magic Circle firms. It does not represent the full partner population — readers should not over-generalise.
It hides the threshold
The firm-side threshold for what counts as an acceptable book varies enormously by firm and is not captured here. Our data is partner-side self-reporting, not firm-side demand.
The sections below break down book size and portability for each major market, followed by practice-area patterns and the archetypes our interviewers encounter most often when portability becomes the sticking point.
The median is not a floor and it is not a ceiling.
Size is what partners report. Portability is what recruiters diligence.
The two do not correlate the way most partners expect. A book has to survive four filters before it arrives at the new platform — and each one shrinks it.
A reported book is not an arriving book. Between “what I bill” and “what lands at the new firm” sit four structural filters our research desk diligences on every conversation. The diagram below is the shape of that attrition, not a measurement of it — it shows the order in which a book narrows, from the gross reported figure to the portion a recruiting firm can actually underwrite.
ReportedWhat actually arrives
- Reported book What the partner bills today — the headline number.
- − Institutional & panel lock-in Work directed at the firm brand or an approved-vendor panel, not the individual.
- − Matter continuity Live files that cannot transfer mid-matter; only future origination is portable.
- − Rate compression Clients that will not absorb the target firm’s standard rate card.
- = Portable book The portion a recruiting firm can underwrite. This is the number that matters.
Across our interview corpus, portability — the assessed likelihood that a partner’s clients will follow them to a new platform — is the single most frequently discussed commercial theme. It surfaces in roughly 400 conversations as a primary topic, more than equity-versus-income (177), culture (138), or conflicts (115). That frequency reflects a structural reality: large books with low portability are economically inferior to smaller highly portable books from a recruiting firm’s perspective, because the book value that matters is the book that actually arrives.
How do reported books compare across London, New York, Paris, and the Gulf?
In our interviews with 2,600+ partners, reported book size and assessed portability differ materially by market. The table below draws on metro-level data from our corpus — suppressed where n < 5.
The table below draws on banded metro-level data from our interview corpus. Currency columns reflect the dominant currency in which partners in each market denominated their books — we do not cross-convert. Portability assessments are drawn from the same conversations; “highly portable” means the partner and our research desk assessed the book as likely to follow the individual to a new platform; “partially portable” means a meaningful fraction would likely transfer; “low portability” means institutional or matter-level lock-in constrains transfer.
What do the metro-level book bands show?
| Metro | Currency | N (book discussed) | N (portability assessed) | Median band | Highly portable | Partially portable | Low portability | Institutional |
|---|---|---|---|---|---|---|---|---|
| London (GBP) | GBP | 60 | 163 | ~£2m | 41 | 75 | 33 | 14 |
| London (USD) | USD | 32 | 163 | ~$3.5m | 41 | 75 | 33 | 14 |
| New York | USD | 68 | 108 | ~$2.5m | 28 | 47 | 23 | 10 |
| Paris | EUR | 32 | 71 | ~€2m | 32 | 32 | 7 | — |
| Dubai | USD | 11 | 32 | ~$2m | 17 | 12 | 3 | — |
| Chicago | USD | 18 | 23 | ~$2.4m | 8 | 8 | 6 | 1 |
| Toronto | USD | 16 | 40 | ~$1.3m | 13 | 14 | 11 | 2 |
| Madrid | EUR | 11 | 16 | ~€1.25m | 2 | 12 | 2 | — |
Banded book ranges (millions): London GBP £0.1m–£20m, London USD $0.1m–$50m, New York $0.1m–$51m, Paris €0.75m–€4.5m, Dubai $1m–$7.5m, Chicago $0.55m–$35m, Toronto $0.17m–$12.5m, Madrid €0.45m–€2.8m. London portability counts are the combined assessed total (nA=163) shown on both currency rows. Source: Sartori Global interview corpus.
Several features of the table stand out. London’s GBP median (around £2 million) is lower than the USD median at the same location ($3.5 million), reflecting the difference between Magic Circle and UK national firm partners on the one hand and US firm London partners on the other. New York’s spread is the widest in the dataset, with books running to $51 million at the top of the range — a figure that belongs to a practice with deal-flow dependency on a single large client relationship and is not representative of the cohort. Paris shows the tightest distribution: EUR-denominated books cluster tightly between €0.75 million and €4.5 million, with very few outliers in either direction, reflecting both the structure of the Paris bar and the predominantly relationship-driven nature of the client base our interviewees describe. Paris also shows the lowest low-portability share of any featured market (10% of assessed conversations), though it is not zero. Dubai skews strongly portable (53% highly portable among assessed conversations) but carries a 9% low-portability share — structural reasons explored below.
Where does each market’s low-portability risk land?
The low-portability share is the single number a recruiting firm cares about most — it is the fraction of a market’s books that institutional or matter lock-in is likely to strand. On this axis the markets fall into a clear order, from London’s one-in-five down to the Gulf’s near-floor. Click or hover any marker for the assessed denominator behind it.
Dubai — lowest low-portability share
3 of 32 assessed conversations. Gulf books are relationship-driven and rarely institutional to begin with, so they skew portable.
Sartori & Partners corpus — nA=32 assessedThe book value that matters is the book that actually arrives.
Why does portability vary so sharply across markets — and what drives it?
Book size is what partners report. Portability is what recruiters actually diligence. The two do not correlate the way most partners expect.
Across our interview corpus, portability — the assessed likelihood that a partner’s clients will follow them to a new platform — is the single most frequently discussed commercial theme. It surfaces in roughly 400 conversations as a primary topic, more than equity-versus-income (177), culture (138), or conflicts (115). That frequency reflects a structural reality: large books with low portability are economically inferior to smaller highly portable books from a recruiting firm’s perspective, because the book value that matters is the book that actually arrives.
How does portability differ between London, New York, and Paris?
London shows the highest institutional count of any major market in our data. Of the 163 London conversations where portability was assessed, 33 partners — roughly one in five — carry books classified as low portability, and a further 15 as institutional. This is primarily a product of panel-driven client relationships at Magic Circle and Silver Circle firms, where major financial institutions, FTSE corporates, and sovereign entities allocate work to the firm rather than to an individual. In our London conversations, a disputes partner at a Magic Circle firm will often describe a substantial reported book but acknowledge that the underlying client instructions are directed at the firm brand, not at them personally.
New York shows a similar pattern (23 low-portability assessments and 10 institutional out of 108 assessed conversations), with 28 highly portable books reflecting the stronger eat-what-you-kill culture at many US firms, where partners are expected to own their client relationships directly. In our interviews with New York partners, the lateral market conversation turns more quickly to minimum transferable book figures than in London, because the presumption is that the book is personal until proven otherwise.
Paris shows the lowest low-portability share of any featured market. Across 71 Paris conversations where portability was assessed, 7 partners (10%) carry books classified as low portability, and none as institutional. Thirty-two were assessed as highly portable and 32 as partially portable — equal splits between the top two categories. In our Paris interviews, this reflects the structure of the French legal market: a relatively concentrated set of large domestic and cross-border corporate clients, long-standing personal relationships built over decades, and a bar that historically prizes individual reputation over firm brand for senior work. The corollary is that Paris books are also narrower in range — the EUR 0.75–4.5 million band reflects a more compressed market than London or New York.
Why do Gulf market books skew toward portable assessments?
Of the 32 Dubai conversations where portability was assessed, 17 (53%) came back as highly portable and 12 (38%) as partially portable — with 3 (9%) classified as low portability. The same structural skew toward high portability holds for the broader UAE cohort. This is not because Gulf-based partners have unusually sticky client loyalty. It is because the Gulf market’s client base is structurally relationship-driven: work in an emerging Gulf market flows through personal networks — government contacts, family office relationships, sovereign wealth fund connections — that sit with the individual rather than with the firm. The books skew portable because they were rarely institutional to begin with.
That structural skew toward portability carries a corresponding risk. Books built on personal relationships in emerging markets are more exposed to key-person dependency, geopolitical risk, and the narrower deal-volume cycles of frontier legal markets. In our Gulf interviews, the absolute book sizes are smaller (median around $2 million USD) and the revenue consistency is harder to verify because matters are episodic rather than panel-driven. A highly portable book in a Gulf emerging market is not the same commercial proposition as a highly portable book in New York.
Which practice areas carry the most — and least — portable books?
Portability is not random. Across our corpus of 2,600+ conversations, it follows clear practice-area patterns that hold across markets.
The portability patterns below draw on the full practice-area portability corpus — not limited to the four featured metros. Practices are ordered from highest to lowest share of highly portable assessments among those where portability was assessed (assessed basis, denominator = n assessed).
How does portability split by practice area across our full corpus?
| Practice area | N (assessed) | Highly portable | Partially portable | Low portability | Institutional |
|---|---|---|---|---|---|
| Insurance | 23 | 12 | 7 | 3 | 1 |
| Banking & Finance | 88 | 38 | 33 | 12 | 5 |
| Technology / Data | 43 | 18 | 21 | 4 | — |
| Regulatory | 29 | 11 | 14 | 4 | — |
| Restructuring & Insolvency | 47 | 16 | 24 | 5 | 2 |
| Private Equity | 27 | 9 | 7 | 4 | 7 |
| Corporate / M&A | 187 | 60 | 79 | 36 | 13 |
| Capital Markets | 58 | 17 | 35 | 5 | 1 |
| Disputes / Litigation | 153 | 44 | 60 | 44 | 6 |
| IP | 84 | 21 | 35 | 22 | 6 |
| Arbitration | 18 | 2 | 11 | 4 | 1 |
Insurance leads with the strongest highly-portable share — 52% of assessed partners carry highly portable books (12 of 23 assessed). Banking & Finance (43% highly portable, 38 of 88 assessed) and Technology / Data (42%, 18 of 43 assessed) follow. Insurance books are typically personal: the partner is trusted as an advocate or negotiator by a claims director or GC, not selected via a panel process. Banking & Finance scores well on portability particularly where the partner has built direct relationships with treasury or legal teams at financial institutions rather than sitting on a firm-managed panel. Restructuring & Insolvency also performs solidly: creditor-side and debtor-side mandates tend to flow from relationships with financial institutions’ workouts teams or insolvency practitioners — relationships the partner built personally over years.
Disputes and IP show the widest spread. In our 153 assessed Disputes/Litigation conversations, high portability (44 conversations, 29%) and low portability (44 conversations, 29%) appear at equal frequency — reflecting the bifurcation between litigation boutiques where the individual partner IS the brand, and institutional litigation departments at Magic Circle and top-20 US firms where the client’s panel instruction goes to the firm. IP (84 assessed) follows a similar split: patent prosecution work is particularly prone to institutional lock-in, while contentious IP work at smaller specialist platforms is often highly personal.
Private Equity shows the highest institutional rate of any practice — 7 of 27 assessed conversations (26%). This reflects the firm-brand dependency of sponsor relationships: large PE houses typically allocate deal work at the firm level, and a single partner departure rarely takes the full sponsor relationship with them, even where the relationship is close.
The portability spectrum, end to end
Read across the practice areas and a single axis emerges: at one end, work that follows a person; at the other, work that follows a platform. Most practices sit somewhere in between, and the same practice can land at either end depending on whether the partner built the relationship or inherited the panel.
Follows the personFollows the platform
- Insurance Trusted by a claims director or GC directly, not via panel — the most personal book in our data.
- Banking & Finance Portable where built on direct treasury / legal-team relationships; sticky where panel-managed.
- Disputes & IP The widest spread: boutique-personal at one extreme, institutional-departmental at the other.
- Private Equity Highest institutional rate — sponsor relationships are allocated at the firm level.
In our conversations with boutique partners, the phrase “I am the practice” appears frequently.
What are the most common portability objections in a lateral conversation?
In our corpus of 2,600+ interviews, 'Client Portability Uncertainty' is one of the most prevalent objection archetypes — and it surfaces differently depending on market and practice.
Across our classified objection corpus (2,789 classified objections across our full interview pipeline), “Client Portability Uncertainty” — defined as the lawyer being unwilling or unable to commit to bringing a portable book — accounts for roughly 7% of all classified objections. It is the sixth most frequent objection archetype in our pipeline, after “Passive Contentment,” “Platform & Brand Downgrade,” “Culture Mismatch,” “Associate Bench Gap,” and “Career Lifecycle Realignment.” But its frequency understates its significance: it is the objection most likely to permanently stall a search, because unlike cultural fit or platform concerns, it cannot be resolved through better positioning or a more attractive package.
How does the portability objection surface in practice — and where does ‘Billing Rate Inflation Risk’ fit in?
Three variants dominate our conversations. First, the institutional lock-in objection: the partner acknowledges a large book but flags that clients follow the firm brand, not the individual — common at Magic Circle and top US-firm partners in London. Second, the panel dependency objection: the partner’s largest clients allocate work through approved-vendor panels that are contracted to the existing firm, not portable by individual departure — common in Banking & Finance, Corporate/M&A, and Capital Markets. Third, the matter-continuity objection: work in progress cannot be transferred mid-matter, so only future origination is portable — common in long-running Disputes and Projects matters.
Client Portability Uncertainty
- Institutional lock-in Clients follow the firm brand, not the individual — Magic Circle & top US-firm London partners.
- Panel dependency Largest clients allocate via approved-vendor panels contracted to the firm — Banking & Finance, Corporate/M&A, Capital Markets.
- Matter continuity Work in progress cannot transfer mid-matter; only future origination is portable — long-running Disputes & Projects.
- Billing-rate inflation Client’s rate tolerance cannot absorb the target firm’s rate card — cross-market moves.
A fourth variant is directly tied to book size by market: Billing Rate Inflation Risk. In roughly 85 conversations across our corpus (about 3% of classified objections), partners describe a mismatch between their existing client’s rate tolerance and the target firm’s standard rate card. This archetype is most prevalent in Disputes/Litigation (20% of its instances), Corporate/M&A (15%), IP (8%), and Projects/Energy/Infrastructure (8%). It surfaces particularly in cross-market moves: a disputes partner at a mid-market platform considering a US firm entry in London, or a Paris-based corporate partner considering a Magic Circle role, may find that their established client base — built at €350–€500 per hour — cannot absorb a step-change to £700–£1,000 rates without the clients choosing to stay with the prior firm instead.
What is the ‘Portable Book of Business’ question archetype in our data?
On the question side of our corpus (1,207 classified partner questions), “Portable Book of Business & Client Retention” ranks seventh most frequent (roughly 7.5% of classified questions) — ahead of Career Trajectory, International Footprint, and Billing Rate questions. Partners use this question block to probe three things: whether the recruiting firm expects a fully formed portable practice immediately, what the minimum transferable book figure is before an equity offer is made, and whether the firm will support a client-development ramp-up period for a partner whose book is partially institutional. In our interviews, partners at boutiques and Silver Circle platforms — where practice-building was part of the original mandate — are significantly more likely to raise this question than Magic Circle partners, who are more likely to flag portability as an objection.
How do book ranges and portability differ across firm tiers?
Across our corpus, books and portability profiles differ not just by market but by the tier of firm the partner is leaving. The pattern is consistent across currencies — but it reads very differently depending on whether you weigh size or portability first.
In our interviews with partners across firm tiers, the most striking contrast is between Magic Circle and Boutique/Specialist: both produce large reported books, but the portability profiles are near-opposite.
What do book ranges and portability look like across firm tiers?
| Firm tier | Currency | N | Banded range | Median band | Highly portable | Partially portable | Low portability | Institutional |
|---|---|---|---|---|---|---|---|---|
| Magic Circle (USD) | USD | 34 | $0.17m–$51m | ~$5m | 14 | 30 | 8 | 5 |
| Magic Circle (GBP) | GBP | 13 | £1.6m–£20m | ~£3m | 14 | 30 | 8 | 5 |
| US Am Law (elite) | USD | 64 | $0.05m–$31.75m | ~$3m | 29 | 24 | 4 | 1 |
| US Am Law (other) | USD | 69 | $0.1m–$40m | ~$2m | 28 | 21 | 10 | 4 |
| International / Global (USD) | USD | 104 | $0.17m–$20m | ~$2.1m | 86 | 92 | 19 | 2 |
| International / Global (EUR) | EUR | 60 | €0.3m–€20m | ~€1.6m | 86 | 92 | 19 | 2 |
| Boutique / Specialist | USD | 49 | $0.3m–$48.3m | ~$2m | 30 | 23 | 6 | — |
| Silver Circle | USD | 21 | $1m–$31m | ~$2.5m | 10 | 12 | 1 | — |
Magic Circle and International / Global portability counts are the combined assessed totals shown on both currency rows. Source: Sartori Global interview corpus.
Magic Circle shows the highest median book size of any tier in our data (around $5 million USD, around £3 million GBP) — but also the highest institutional rate and a portability profile skewing toward “partially portable.” In practice, a Magic Circle partner with a $5 million reported book and a “partially portable” assessment is a more complex lateral proposition than a Boutique/Specialist partner with a $2 million book and a “highly portable” assessment — because the book that actually arrives at the new platform may be similar in absolute size.
Weigh portability first and the ranking inverts: the tier with the biggest median book is not the tier whose book most reliably arrives.
Which tiers carry the most portable books relative to size?
| Firm tier | Portability read |
|---|---|
| US Am Law (elite) | The most favourable portability profile relative to book size of any tier we track — median around $3m with 29 highly portable, 24 partially portable, and just 4 low-portability assessments, reflecting the American model of partner-owned client relationships. |
| Boutique / Specialist | Lower median books but very strong portability, because boutique practices are almost entirely personal by design. The phrase “I am the practice” appears frequently in these conversations. |
| Magic Circle | Highest median book of any tier (~$5m USD / ~£3m GBP) — but the highest institutional rate and a profile skewing “partially portable,” making a large reported book a more complex proposition than it looks. |
| International / Global | The largest assessed cohort, skewing highly and partially portable (86 and 92) with relatively few institutional assessments — but a lower median band (~$2.1m USD / ~€1.6m EUR). |
US elite Am Law shows the most favourable portability profile relative to book size of any tier we track: a median around $3 million with a portability split (29 highly portable, 24 partially portable, 4 low portability) that reflects the American model of partner-owned client relationships. Boutique/Specialist mirrors this pattern: lower median books but very strong portability, because boutique practices are almost entirely personal by design. In our conversations with boutique partners, the phrase “I am the practice” appears frequently — and our portability assessments reflect it.
A $5 million reported book with a “partially portable” assessment is a more complex lateral proposition than a $2 million book that is highly portable.
What should partners understand about their own book before engaging the lateral market?
The lateral market will diligence your book — size, currency, portability, and client concentration. Knowing your own numbers before the conversation starts changes how it goes.
In our interviews with more than 2,600 partners, the conversations that stall most predictably are those where the partner has not interrogated their own portability before picking up the phone. Size is the easy part. Portability requires honest answers to four questions the recruiting firm will ask regardless.
Which four questions determine whether a lateral book stands up to diligence?
| Question | What it is actually probing |
|---|---|
| Are the clients relationship-loyal or platform-loyal? | A general counsel who has instructed you personally across multiple moves is relationship-loyal. A company whose matter is panel-managed by procurement is platform-loyal — and will likely stay with the firm. |
| Can you name the decision-maker at each client? | If you cannot name a specific individual who would take the call and agree to follow you, the client is institutional. Naming a team or a department is not the same as naming a relationship. |
| What happens to rate at the new platform? | If the target firm’s standard rates are materially above what your client base currently pays, a rate increase is built into the move. In our data, this is the primary mechanism by which portable books shrink on transfer. |
| Is there matter continuity that keeps the work at the current firm? | Ongoing matters — particularly in litigation, arbitration, and large project finance — often cannot be transferred mid-file. The portable portion of the book is next-instruction origination, not existing work. |
For partners at Magic Circle or top-20 firms considering a move to a US platform in London, the rate question is structurally the most dangerous. In our London corpus, this is one of the dominant themes in the “Billing Rate Inflation Risk” objection archetype: a partner whose book was built at Magic Circle rate levels may find that US firm standard rates require client-by-client grandfathering discussions before the lateral can proceed.
For partners considering cross-market moves — from Paris to London, from London to Dubai, or from a US domestic market to an international platform — the portability calculus changes further. Our data on Paris shows high portability because French-market client relationships are personal. But that portability is denominated in EUR and constrained by the compressed range of the Paris market. A Paris partner moving to London brings a portable book in EUR terms that may look smaller to a GBP-benchmarked London firm than the absolute number suggests, without any currency conversion applied.
Partners thinking about their own position in the lateral market should read our guide to lateral partner hiring economics alongside this data — it covers how firms structure the financial offer and what the diligence process looks like from the recruiting side. If you are a partner currently mapping the market, speak to the Sartori & Partners research desk for a market-specific read on how your book is likely to be assessed.
Every figure here traces to one cited, described dataset.
We do not publish numbers we cannot account for. Every figure on this page is a banded aggregate from Sartori Global's proprietary interview corpus of approximately 2,667 partner-level conversations — described in full below, with cells of n < 5 suppressed and currencies never cross-converted.
The dataset and companion reading
6 referencesBook medians and ranges are banded; no point figure is attributable to a single person, firm, or practice. The corpus skews toward active or open-to-move candidates at international, US, and Magic Circle firms and carries survivorship bias — readers should not over-generalise to the full partner population. For the compensation side of the same lateral equation, see our partner pay benchmark for the Am Law top 50.
Partner book of business: common questions
How large is a typical portable book of business for a lateral partner in London?
Across more than 100 London partner conversations in our interview corpus, GBP-denominated books cluster in the £1–£4 million band, with a median around £2 million. USD-denominated books at London-based partners (commonly at US firms with London offices) show a wider spread and a higher median near $3.5 million. Neither figure represents a clean 'market minimum' — Magic Circle and Silver Circle firms typically expect more, boutiques and Silver Circle practices sometimes accept less — but the £2 million GBP band is where most London lateral conversations start. Portability is a separate question from book size: of the 163 London conversations where portability was assessed, 33 partners — roughly one in five — carry books classified as low portability, because institutional clients, panel relationships, or matter continuity keeps work with the platform rather than the individual.
Are partner books in New York genuinely larger than in London or Paris?
In our interviews with 69 New York-based partners who discussed book size, the median USD book lands around $2.5 million — comparable to London's USD-denominated cohort but below the upper end of that range. The New York distribution is, however, wider: books run from under $1 million to above $50 million in the same city, reflecting the concentration of both rainmaker partners and platform-reliant service partners in the same market. Paris, by contrast, shows a tighter EUR-denominated band (median ~€2 million, range roughly €0.75–€4.5 million), which reflects both the smaller size of the Parisian lateral market in our pipeline and the predominantly EUR-denominated client base. Raw size comparisons across cities are complicated by the fact that currencies are not cross-converted in this analysis.
Why is book portability structured differently in emerging Gulf markets compared to London or New York?
In conversations with partners based in Dubai and across the UAE, the portability profile differs from London or New York. Of the 32 Dubai conversations where portability was assessed, 17 partners (53%) carry highly portable books, 12 (38%) partially portable, and 3 (9%) low portability — a low-portability rate considerably below London (20%) or New York (21%), but not zero. That concentration toward high portability reflects a structural feature of the Gulf market: many Dubai-based partners at international firms originate work through personal networks built across jurisdictions — client relationships that sit with the individual rather than the firm. The corollary is that books in these markets tend to be smaller in absolute terms (median around $2 million USD) and more exposed to relationship risk if key contacts move. Portability skews high because the book is relationship-driven, not because the book is large.
Which practice areas show the highest partner book portability across markets?
Across our full interview corpus (assessed basis — excludes conversations where portability was not assessed; denominator = n assessed), Insurance leads with 52% of assessed partners carrying highly portable books. Banking & Finance and Technology / Data follow, with 43% and 42% of assessed partners respectively assessed as highly portable. Regulatory (38%) and White Collar / Investigations (35%) round out the top five. Banking & Finance scores well on portability particularly where the partner has built direct relationships with treasury or legal teams at financial institutions rather than sitting on a firm-managed panel. By contrast, Disputes/Litigation and Corporate/M&A show the most mixed portability profiles — high portability is common where the partner has built a sector-specific reputation, but low portability (29% in Disputes, 19% in Corporate/M&A) is also frequent where work is panel-driven, where the matter is ongoing and administratively locked, or where a large institutional client follows the firm.
What is the minimum book of business a firm typically expects from a lateral partner hire?
Our data does not capture firm-side threshold requirements directly — it captures partner-side self-reporting. What the corpus does show is that 'Client Portability Uncertainty' is among the most common objection archetypes in our pipeline, cited in roughly one in fourteen classified objections across more than 2,700 conversations. Partners frequently describe a mismatch between what a target firm demands and what they can realistically bring. One recurring theme is that panel-driven practices cannot meet €5 million thresholds regardless of total book size. In practice, the functional minimum varies sharply by market, tier, and practice: a disputes partner at a US firm entering London on a build mandate may be evaluated more generously than a corporate partner approaching a Magic Circle firm with an established practice to protect.
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London partner compensation bands across Magic Circle, Silver Circle, and US firm London offices — the market the book travels into.
Read London partner payAssociate Rates Leaked: What Court Filings Reveal
How elite firm billing rates have moved — context for the rate-inflation risk that sits inside partner book portability across markets.
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Our research desk maps partner books, portability profiles, and firm-side thresholds across London, New York, Paris, and the Gulf. Tell us your practice and market and we will give you the unfiltered read.