The Clients You've Been Serving at a Loss for Years
A firm bills $6 million a year and clears 13 percent margin. Healthy enough on paper. Inside that number sit 40 clients, and if you ranked them by the profit they actually throw off, the top 10 would be quietly carrying the bottom 15. The owner almost never knows which client is which, because the accounting system tracks revenue by client and cost by department, and those 2 views never meet on a single line.
In a product business the leak is freight and returns. In a services business it's time. Money doesn't escape at the invoice. It escapes between the hours your people worked and the hours you actually put on a bill, and again between the hours you billed and the dollars that came back. That second gap has a name. Realization. It's the fraction of your standard fee you keep after write-downs, discounts, and the time nobody wanted to fight about.
Firms that benchmark this put average billing realization somewhere around 89 to 91 percent, and treat anything under 85 percent as a warning light, according to advisory groups that track professional services metrics. A rate that low usually means scope that grew without a conversation, engagement letters written loosely, or a manager who writes down a junior's hours every month rather than explain them to a client. None of it shows up as a loss. It shows up as work that felt busy and paid less than it should have.
The oldest client is the usual suspect
Picture the account you've had for 12 years. The rate hasn't moved in 6 of them. The scope has crept every single year, a favor here, a rush request there, a standing call that used to be quarterly and is now weekly. Nobody ever renegotiated because nobody wanted to risk the relationship, and the client became part of the furniture. That's the one to check first.
Long-tenured clients drift below cost so slowly that no single year looks wrong. Your costs rose. Salaries rose. Their fee sat still while the work they expect kept expanding. By the time you notice, you're staffing a senior person on an account priced for the associate who ran it in 2019. The loyalty is real and it runs both directions, which is exactly why it never gets priced. You're subsidizing your most trusted relationship and calling it a good client.
Run the math at the engagement level, not the client level
The client average hides as much as the firm average does. A client can be profitable overall and lose money on 2 of the 4 things you do for them. So you go one level down.
Take your 10 largest accounts. For each engagement, pull the hours your people actually worked, not the hours that reached an invoice. Multiply by a real loaded cost per hour, the salary and the overhead, not the rate card. Then compare that to what you collected on the engagement after every write-down and discount. You're not chasing accounting precision. You're chasing rank order. You want to know which engagements earn their keep and which ones you've been donating.
Watch what one lever does when you find the problem. Analysts who model these firms note that a 5-point move in any single driver, the bill rate, utilization, or realization, can swing EBITDA margin by 3 to 8 points. That's the whole reason this is worth an afternoon. The engagement that's bleeding you doesn't need to be fired. It needs one of 3 numbers moved, and a small move is enough.
What you do with the answer
You reprice, you rescope, or you resource it differently. Usually some of each.
Reprice the relationship that has been frozen since before your costs went up, and do it as a scheduled review rather than a confrontation, so it happens every year instead of never. Rescope the account that has been getting 15 percent more than it pays for, by writing down in plain language what the fee covers and what it doesn't. Where price genuinely won't move, move the labor instead. The senior partner running a routine account by hand is the most expensive way you could possibly deliver it, and often the client would never notice a well-briefed associate doing the same work.
Then find the quiet, high-realization client nobody worries about, because it never causes trouble, and treat it like it matters before someone else offers it a reason to leave.
Pull your 10 biggest engagements this quarter and put worked hours next to collected dollars on each one. You will find at least one you've been running at a loss since before you can remember. Fix that one and you've paid for the exercise.