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Blog · Board and management reporting · Consulting and advisory

Partner book concentration: the risk a fee report hides

How a consulting, advisory or law firm measures concentration per partner from billed fees: the share of fees from the top three clients, the count of clients to eighty percent, the trend over three years, and why a partner with a strong fee number and a concentrated book is the firm's largest unmanaged risk.

The short answerMeasure concentration per partner as the share of billed fees from the top three clients and the number of clients that make up eighty percent of the book, computed from the practice management export every quarter and read as a three-year trend. A partner at seventy percent from three clients has a book that one departure halves. The measure is invisible in a fee report, which rewards the same concentration it should flag.

A partner's fee number tells the firm how much the partner billed. It does not tell the firm how many clients that number depends on, and the difference between a broad book and a narrow one at the same fee level is the difference between a resilient partner and a single point of failure. This guide sets out concentration per partner and the trend that matters more than the level.

The measures

Per partner, per year:

Top-three share = fees from the three largest clients ÷ total fees Clients to 80% = the number of clients, largest first, needed to reach 80 percent of fees

Per practice and firm:

The distribution of both measures across partners, and the trend for each partner over three years

The rows you need

  • Billed fees: client, partner, period. From the practice management export.
  • Relationship lead: where a client has more than one partner, who leads. Otherwise the client is counted under each partner working it, and the firm-level concentration is overstated.

Client identifiers only.

The roll-up

  1. Partner by client by year: fees.
  2. Partner by year: ranked clients, top-three share, clients to 80 percent.
  3. Practice and firm: distribution and trend. Assert that client fees by partner sum to billed fees.

billed fees = Σ partners = Σ clients

A worked example

Four partners, this year, with the three-year trend.

Partner Fees Top-three share Clients to 80% Three years ago Reading
A £2.4m 31% 11 34% Broad, stable
B £2.9m 71% 3 44% Narrowing fast
C £1.1m 55% 4 58% Concentrated, stable
D £1.8m 28% 14 30% Broad

Partner B has the highest fees in the group and the largest risk: three clients are 71 percent of a book that was 44 percent concentrated three years ago. The fee report ranks B first. The concentration report says B's book would halve if one relationship ended, and that the narrowing is recent. Both are true, and only one of them is a management conversation.

What the firm does with it

  • A second partner introduced to the largest relationship, so the client knows the firm and not only the partner.
  • Cross-practice gaps on the concentrated clients worked first, because deepening the relationship across practices is the firm's best protection.
  • New client development targets for the partner, weighted toward the narrowing.

Where it goes wrong

Group clients split. Subsidiaries as separate clients make every book look broader than it is. Roll up to the group.

Joint clients double counted. A client under two partners inflates both books and the firm's concentration. Name the relationship lead.

One year only. A single year's concentration is a snapshot. Three years is a direction.

Read as a league table. Concentration is a risk measure, not a performance one. Presented as a ranking it produces defensive partners and hidden clients.

Every quarter, by partner

Mapped once, the fees export produces concentration and its trend per partner every quarter, reconciled to billed fees, with scope so each partner sees their own. Covirage builds this from the export as it is, client identifiers only. The consulting and advisory page and the law firms page describe the setups, and the cross-practice guide covers the growth measure from the same export.

Questions people ask

What concentration is too high?

There is no universal line, but a book where three clients exceed half the fees, or fewer than five clients make up eighty percent, is one the firm should be looking at. The more useful reading is the trend: concentration rising over three years is a partner whose book is narrowing.

Is concentration always bad?

No. A partner who runs one large relationship superbly is valuable. The risk is unmanaged concentration: the firm not knowing, and no second partner on the relationship. The measure exists so the firm knows.

Can partners see each other's concentration?

The managing partner and the practice heads see it by partner. Each partner sees their own. Client identifiers stand in for names.