Portable Book of Business: How Much Do Partners Need?

Dear Marcus O.,

Understanding Portable Business in Today's Market

A portable book of business represents the clients, relationships, and revenue that you can reasonably expect to bring with you in a lateral move. It's not just about historical billings—firms are evaluating your ability to generate sustainable business at your new platform.

The concept has evolved significantly. Firms now conduct deeper due diligence on client portability, often requiring detailed breakdowns of your origination history, client contact patterns, and realistic transfer probabilities. Simply having your name on large matters isn't enough if you're not the primary relationship holder.

Revenue Expectations by Firm Tier

Am Law 100 firms often expect partners to demonstrate substantial portable business, with figures commonly ranging from $2-5 million annually, though this varies significantly by firm, practice area, and market. Corporate partners in major markets like New York or Silicon Valley may face higher expectations, with some firms seeking partners with $5-10 million or more in portable business—while specialized practices or emerging markets may have more flexibility.

Regional powerhouses and Am Law 200 firms may have different expectations, with some considering partners with smaller but growing books of business. The key is showing growth trajectory and market opportunity, not just current billings.

Consider using a partner portable book calculator to help quantify your realistic transferable revenue based on client relationship strength and matter types.

Practice Area Variations

Litigation partners often face unique challenges since client relationships may be tied to specific disputes rather than ongoing needs. However, the current market shows strong demand—particularly in employment law where California's PAGA landscape and wage-hour class actions have created opportunities, though legal requirements continue to evolve.

Corporate and transactional practices typically have clearer portability metrics. M&A partners can point to specific client relationships and deal flow, while regulatory practices in hot areas like privacy, AI, and ESG command premium valuations even with smaller books.

In growing markets like Charlotte, where major financial institutions drive substantial financial services demand, firms are more willing to invest in partners with strong but developing books, especially those bringing expertise from major markets.

Beyond the Numbers: Relationship Strength Assessment

Firms increasingly focus on relationship quality over pure revenue figures. They want to understand: Are you the primary contact? Do clients call you directly? Have you moved clients before successfully? Can you demonstrate organic business development success?

Strong indicators include serving as outside general counsel relationships, handling repeat engagements across multiple years, and having direct CEO or general counsel access. Weak indicators include primarily working as execution counsel on matters originated by others or having relationships tied to a specific partner who isn't moving with you.

Strategic Positioning for Different Scenarios

If your portable book is below typical thresholds, focus on market opportunity and specialized expertise. The Pacific Northwest's tech-heavy market, for example, values partners who understand the unique dynamics of noncompete restrictions and H-1B dependent employers, even if their current book is modest.

Partners with substantial books should prepare detailed client-by-client analyses, including transfer probability assessments and growth projections. Firms want to see your business development methodology and expansion plans, not just current billings.

Consider market timing carefully. Many Am Law 100 firms have reported revenue growth in recent periods and actively expanding in emerging areas like AI transactions and ESG compliance, creating windows for partners who might not meet traditional thresholds but bring cutting-edge expertise.

Practical Due Diligence Preparation

Start documenting your business development activities well before any move. Track origination versus execution work, maintain records of client development investments, and prepare realistic portability assessments for each major relationship.

Remember that firms often discount claimed portable business significantly in their initial evaluations, then rely on actual transfers to validate your projections. Being conservative and exceeding expectations typically serves better than overpromising and underdelivering.

The lateral market has shown strength in recent periods, particularly for partners who can demonstrate both relationship strength and expertise in high-demand areas. Focus on building a compelling narrative around your business development trajectory rather than just current numbers.