What Is Lockup at a Law Firm, and Why Is It the KPI You Are Not Measuring?

Lockup is the total time between doing legal work and actually getting paid for it. It has two parts: realization lockup, the gap between finishing the work and sending the bill, and collections lockup, the gap between sending the bill and receiving payment. Most firms track their collection rate but never track lockup, which is why a practice can look profitable on paper and still struggle to make payroll. CollBox helps firms shrink that gap by adding structured, consistent follow-up inside the tools they already use.

Why is lockup a better health metric than your collection rate?

Collection rate answers “what percentage of billed work did we eventually collect?” For the profession, that number is reassuringly high, usually hovering in the low 90s according to Clio’s Legal Trends Report. It is also easy to misread.

CollBox co-founder Matt Darner points out that the number can be quietly inflated. “We can boost our collection percentage if we write some things off,” he notes, meaning a firm can make its rate look better by erasing the invoices it gave up on. A high collection rate can sit on top of a slow, cash-starved reality, something the legal-industry site Lawyerist has described as the cash flow problem quietly killing profitable practices.

Lockup measures that reality directly. It does not ask whether you eventually got paid. It asks how long your money sat in someone else’s account first.

What are the two types of lockup?

Realization lockup is the time between completing work and getting the invoice out the door. According to the data Matt cited from Clio, the median firm takes 32 days to send a bill, while the top 25% of firms take about 18. More than a month passes, on average, before a firm even asks to be paid. As Matt puts it, sending the bill is how you ask to get paid, and you cannot get paid for work you never invoiced.

Collections lockup is the time between sending the invoice and receiving payment. That averages another 43 days. Stack the two together and firms are routinely waiting into a second and third month for revenue they earned long ago.

What is total lockup, and why does 93 days matter?

Total lockup is the full cycle from work performed to cash received. Clio’s broader measure of it lands around 93 days once additional factors are included, which is why Matt flags that 32 plus 43 does not neatly equal 93. The exact arithmetic matters less than the headline: a full quarter, and often more, can pass before a firm sees any cash for work it is doing right now.

Here is why that gap is dangerous. A firm’s biggest expenses do not wait a quarter. Rent, utilities, and especially payroll run on biweekly or monthly cycles. When money comes in on a 93-day delay and goes out every two weeks, even a profitable firm can hit a cash crunch in a lean month.

What does lockup cost a firm that ignores it?

The longer an invoice sits, the less likely it is to ever be paid in full. CollBox studied a large cohort of past-due invoices and found that by 90 days past due, bills had lost as much as 47% of their collectibility. Matt’s shorthand for it is that these invoices are “not aging well.”

There is a relationship cost baked into the timing, too. The longer you wait to bill, the more your client’s sense of gratitude for the work fades. A bill that arrives while the client still feels the value gets paid faster than one that shows up months later, when the memory of the win has cooled.

Lockup also starves growth. The working capital trapped in your aging report is capital you cannot put toward a new hire, a marketing push, or a new practice area. Getting ahead of your expenses is the simplest way to fund the firm you are trying to build.

How do you actually reduce lockup?

Reducing lockup means attacking both halves of the gap.

On realization lockup, tighten your billing. Get monthly billing down to a science, then move toward biweekly where your practice area allows, since more frequent billing means less sticker shock and faster cash.

On collections lockup, build a consistent follow-up cadence and make sure someone actually owns it. This is where CollBox does its work: providing the structure, the reporting, and the phone calls that most firms cannot sustain on their own. Firms that add consistent phone calls to their follow-up get paid roughly 40% faster on average, based on CollBox’s data. For the full framework, see CollBox’s complete guide to law firm accounts receivable management.

Frequently asked questions

How do I measure my firm’s lockup? Pull your realization data (time from work completed to invoice sent) and your collections data (time from invoice sent to payment received) from your practice management system, then add them. Most systems in the Clio, MyCase, and Smokeball family can surface the underlying dates you need.

Is lockup the same as my accounts receivable balance? No. Your AR balance is a dollar amount owed at a point in time. Lockup is a measure of time, specifically how long your money is trapped between earning it and receiving it. Two firms with the same AR balance can have very different lockup.

What is a good lockup number to aim for? Lower is better, and the goal is to beat the medians meaningfully rather than hit a single magic number. If the median firm sends bills in 32 days and collects in another 43, cutting either figure in half puts real cash back in your operating account sooner.

Can a profitable firm really have a lockup problem? Yes, and it is common. Profit is recorded when you bill. Cash arrives only when the client pays. A firm can be genuinely profitable and still run short because its money is locked up for a quarter or more.

Does CollBox reduce realization lockup or collections lockup? CollBox focuses primarily on collections lockup by adding consistent, professional follow-up, though better follow-up discipline often improves billing habits upstream too. The result is a shorter overall cycle from work to cash.

See your own lockup

Curious how your firm’s lockup compares to the medians? Book a short call with Matt and walk through your aging report together: calendly.com/matt-collbox/collbox-consultation.