I don’t usually receive a call after an attorney has their best month on record. This one was different. She told me about 41 new files in 30 days, all of them from one carrier. Insurance defense, a solo with a paralegal and a part-time associate in insurance defense. We figured her overhead was under 15%, about $620K had been collected that year. She was from Fort Worth, and it was March 2025. I figured the call was about hiring, but the truth is she had worked something out over the weekend and wanted to tell somebody who’d know what she meant. That work led her to tell me she was at full capacity. Every hour in the month was booked before the month started. She no longer had time on the calendar to meet with the two local agencies that would send her some work. Then she left the bar section she’d chaired for four years. She finished the busiest month of her career, believing she had never done so much work and that she was at her ceiling. I’ve had that call before. The details move around, but the conclusion never does. Full calendar, so time must be the problem.
She was right about the calendar. Every hour was spoken for. The conclusion she came to, that time is the constraint on the firm, is the claim we’re about to test. We call this letter The Billable Hour, so it seems right to run the breakdown here.
Two owners, one full week
We’re going to take a look at two owners with identical weeks.
The first is the owner on the phone. Trace her hours file by file, and they land at about 45% of collections running through a single carrier. This is the work that ended the agency lunches mentioned earlier. The stopped lunches are what let the referral work go quiet. The quiet referrals increased the dependence on the single carrier. Her hours are full because one claims department’s assignment queue decides what her week looks like. The calendar is where concentration shows up.
Let’s compare that to a fixed-fee estate planning practice. Same gross over the same time period. Trace his hours, and they pool in package work priced in 2022, and nobody has ever calculated what those hours pay per owner hour. The collection is where the number moves. At solo and small firms, about 14% of billable work never reaches an invoice, and roughly a tenth of what is invoiced goes unpaid (Clio Legal Trends Report). His hours are full because a growing share of the week earns an effective rate nobody has looked at.
Same felt problem, but the constraint that binds each firm is different, and so is the fix. Get that wrong, and you execute the right answer to the wrong problem, at full cost and zero effect. I’ve watched owners do it. I’ve done it on my own firm (not recently), which is the kind of thing you’re not supposed to admit in a letter about diagnosis.
Where the hour comes from
Here’s the mechanism. The owner’s hour is the surface where everything that binds a one-owner firm shows up, because there’s one calendar and everything in the firm clears through it. A demand problem shows up as hours spent chasing work. A pricing problem shows up as hours that collect less than they billed. A concentration problem shows up as a calendar one client controls. The hour registers all of it and identifies none of the causes.
Which is why tracing what consumed the hour, matter by matter, is the diagnostic act, and treating the hour itself as the problem is a product category. The time-management shelf sells calendars to lawyers, but a better calendar just reorganizes the symptom.
The two numbers to pull this afternoon
Two numbers decide the read, and your reporting produces neither. Both come from figures you already have.
Contribution per owner hour, by matter type = (collected on that matter type - the direct cost of producing it) / owner hours it consumed
Practice management software reports billed hours and gross revenue. This number lives in the gap between those two reports, which is how the work that fills most of a week can pay the least per hour for years without anyone noticing. After collection, the ranking of what a week is worth rarely matches the ranking of what fills it.
Concentration = the largest relationship’s trailing twelve months of collections / the firm’s trailing twelve months of collections
You can name the anchor from memory, the client or the carrier. Stating the share is different work, and the share is the number a lender, a bad quarter, or one change of adjuster will eventually state for you. There’s a share of collections above which a relationship stops being a client and starts being the firm’s structure. That zone is real. Where the line sits for your firm depends on your own decomposition.
Pull the anchor’s collections for the last twelve months and divide. Then pull one matter type, the one that filled the most hours, and run the first formula. Do those two and you’ll know more about the firm than the full calendar has told you all year.
The top 3% of solos gross $600K to $1 million and above (Clio Legal Trends), and nearly all of them arrive there on full calendars. The hour is evidence. A full week tells you a constraint exists, just not which one.
If the concentration number came back higher than you expected. The Growth Intelligence Scorecard reads your firm’s revenue structure from the numbers you already carry. About four minutes in your browser, no meeting. growthprolegal.com/scorecard
This letter is not legal advice and is not accounting advice.
The analysis in this letter is produced under Revenue Intelligence & Decision Architecture (RIDA), the proprietary economic discipline B.L. Sheets & Co. runs on and runs for the firms it serves. The doctrine, the case record, and the engagement formats are at blsheets.co.
Sources. Clio Legal Trends Report: realization and collection figures (14% of billable work unbilled at solo and small firms, roughly a tenth of invoiced work unpaid) and the solo revenue distribution (top 3% grossing $600K to $1 million and above). Both owners are composites drawn from engagement work, rounded and anonymized per the standing rule.