Mind the gap: Why the cash gap matters more than profit

Profit is important, but in our work with SME law firms across Australia, we have seen that cash flow is what keeps a firm running smoothly. A firm can post a healthy accounting profit for the year and still miss payroll in July, delay a partner distribution, or turn down a growth opportunity because the money is not in the account when it needs to be. The reason is almost always the same: the gap between doing the work and being paid for it has quietly widened. This piece explains what the cash gap is, how to measure it, why it matters more than the P&L, and the practical work involved in closing it.

The cash gap explained

In a law firm, the cash gap is mainly driven by work in progress (WIP) that has been completed but not yet billed, and invoices that have been issued but not yet paid. Overheads such as wages, rent and tax still need to be paid while that revenue is sitting in the ledger rather than the bank.

Every firm has a cash gap. That is normal. What is not normal is how wide the gap is allowed to grow, and how invisible it stays until it becomes a problem. Slow payment terms, end-of-matter billing, discretionary billing across fee earners, and undisciplined debtor follow-up all widen the gap. Every extra day added to the cycle is a day of your revenue sitting in someone else’s bank account instead of yours.

A common measure used to track this is lock-up, which can be expressed as lock-up days or lock-up percentage. It combines unbilled WIP and unpaid debtors into a single number that answers a simple question: how many days of revenue is your firm carrying as working capital?

Why the cash gap matters more than profit

You cannot pay wages, rent, tax or partner drawings out of accrued profit. You pay them out of cash. When the cash gap widens, the firm’s ability to operate erodes even when the accounts are technically in the black.

A wide cash gap creates three related problems:

• Working capital drains. The firm needs to fund the gap out of retained earnings, an overdraft, or a partner injection. Each option has a real cost, and each one gets more expensive as the gap grows.
• Growth stalls. Hiring a new fee earner, opening a new office, adopting new technology, or investing in marketing all require cash. If working capital is tied up in the ledger, those decisions get deferred or watered down.
• Risk compounds. The longer WIP and debtors sit, the harder they can become to resolve cleanly and the greater the pressure on billing discipline and debtor follow-up.

The scale of the impact is often larger than principals realise. Because lock-up represents revenue already earned but not yet converted into cash, even a modest reduction can release significant working capital back into the firm’s general account, without needing to win new work or increase fees.
That is the argument in one paragraph. Improving the cash gap can be one of the most practical ways for a law firm principal to release cash the firm has already earned. It does not require winning new work, hiring new fee earners, or reducing overhead. It requires tightening the operational discipline around billing and collections.

How to measure the cash gap

The two working measures used across the profession are lock-up days and lock-up percentage. Both start with the same components: unbilled WIP plus unpaid debtors, expressed against annual fee revenue.
A common way to calculate lock-up days is:

Lock-up days = (Debtors + WIP) ÷ Annual fee revenue × 365

A worked example makes it real. A firm with $1.2 million in annual fees, $120,000 in debtors and $55,000 in unbilled WIP has $175,000 in lock-up. That is 53 days of lock-up. The same firm with tightened billing discipline might carry $90,000 in lock-up, or 27 days. The difference is $85,000 of cash that either sits in the ledger or sits in the bank.

Lock-up percentage is the same number expressed as a share of annual revenue. In the example above, 53 days is 14.5% of annual fees. FWO’s guidance is that best-practice firms aim for lock-up below 20%. Once lock-up rises above that level, it is worth reviewing WIP, debtor follow-up and billing discipline closely.

The number only becomes useful when it is watched. Firms that measure lock-up monthly and hold fee earners accountable to it close the gap faster than firms that produce the number once a year at tax time. This is one of the reasons our MiNumbers dashboards surface lock-up as a headline metric, alongside average rate and fee earner productivity.

Six sources of a widening cash gap

When a firm’s cash gap grows, it is almost always for one of six reasons.

1. End-of-matter billing. The classic culprit. Matters that only bill on completion trap months of WIP with no cash flow return until they close. Progress billing is one of the most practical levers available.

2. Fee earner discretion in write-offs and delays. When individual fee earners decide when and how much to bill, the firm’s cash position sits on the desks of everyone with a billing licence. We covered the mechanics of this in our companion piece on discretion.

3. Weak debtor follow-up. Invoices that go out are not the same thing as invoices that get paid. Older debtors often indicate that follow-up processes need attention. The longer invoices remain unpaid, the more important it becomes to have a clear and consistent debtor management process.

4. Loose engagement and payment terms. Loose engagement and payment terms can leave the firm with fewer practical levers when payment slows. Clear billing frequency, payment expectations and engagement terms agreed upfront reduce the risk before it becomes a debtor problem.

5. Time capture that lags reality. WIP that goes into the system a week or a month late becomes harder to bill at full value. Daily time entry is a boring habit that has an outsized effect on lock-up.

6. No visibility of the number. Firms that do not track lock-up monthly cannot see the gap growing. The problem reveals itself when a big overhead bill or tax obligation lands on a thin bank balance.

How to close the cash gap

The good news is that the mechanics of closing the gap are well understood. The work is operational rather than clever. Six habits, applied consistently, do most of the job.

• Bill monthly, not at the end of the matter. Progress billing is the single highest-yield lever available.
• Implement staged billing on longer matters and confirm the schedule with the client at engagement.
• Take retainer deposits at engagement wherever the matter type and regulatory framework allow. Reduce risk before it becomes a debtor problem.
• Automate reminder cycles. Use the practice management system’s built-in workflows so follow-up does not depend on someone remembering.
• Remove fee earner discretion over billing decisions. Centralise billing under a nominated partner or the practice manager.
• Monitor lock-up percentage monthly via MiNumbers or your practice management system. Publish the number to fee earners so it becomes a shared metric, not just a partner conversation.

None of these are novel. What matters is committing to all six and holding the discipline. Firms that apply these habits inconsistently may find improvements harder to sustain. Firms that treat the cash gap as a whole-firm behaviour change are better placed to turn earned revenue into usable cash more consistently.

What good looks like: a practical lock-up guide for law firms

Benchmarking gives principals something concrete to discuss. FWO’s published guidance is that best-practice firms aim for lock-up below 20%, while the right target for your firm will depend on practice area, matter length, billing model and client mix.

• Lower lock-up. A firm with disciplined progress billing, clear payment expectations and consistent debtor follow-up is more likely to convert work into cash quickly.
• Moderate lock-up. If WIP and debtors are being monitored monthly and cash flow remains steady, the firm may be in a manageable position, but there is usually still room to sharpen billing discipline.
• Rising lock-up. When WIP and debtors continue to grow, working capital becomes tied up and cash flow pressure can become more visible around BAS, tax, payroll and partner distribution dates.
• High lock-up. A high lock-up position can mean the firm is funding client work for too long before being paid. This can restrict growth, increase pressure on reserves and make debtor management more difficult.

Some practice areas and matter types naturally have longer billing cycles than others. That is why lock-up targets should be set in context, rather than copied from another firm without considering matter length, payment terms and billing model.

Lock-up can also matter when a firm is preparing for succession, merger or sale. A firm with cleaner WIP, stronger debtor control and more predictable cash flow is generally easier to assess and present than one carrying a large amount of unbilled or unpaid work.

How FWO helps law firms close the cash gap

FWO Chartered Accountants was founded in Brisbane in 1992 and brings more than 30 years of legal industry expertise to its work with SME law firms. Closing the cash gap is a practical place to start because it can release cash the firm has already earned and it clears the operational static so the higher-value conversations become easier to have.

A typical engagement covers:

• Reviewing your current lock-up alongside the two numbers FWO identifies as key drivers of law firm profitability and cash flow: average rate and lock-up.
• Diagnosing the specific causes of the gap in your firm, from time capture practices through to debtor follow-up. Our Grow Your Firm advisory program supports this through structured reporting, interpretation and accountability.
• Implementing MiNumbers dashboards so the firm can monitor WIP, debtors, cash flow, fee earner performance and forecast movement with clearer visibility.
• Working with the practice manager to review billing frequency, payment expectations and debtor processes so the operational settings support the finance goal.
• Reviewing the numbers through a structured reporting rhythm and helping partners and fee earners stay accountable to agreed financial targets.

The work is not glamorous. It is habitual. But over time, consistent billing discipline and better lock-up visibility can make a meaningful difference to cash flow and financial confidence.

Ready to close your cash gap?

Cash is the oxygen of your business. A profitable firm with a wide cash gap has already done the hard work of winning and delivering the client work. It just has not finished the job.

If you want to see where your lock-up sits, what a realistic target looks like for your firm, and how much cash is currently sitting in the ledger that could be in your general account, we can help you map it in a single session.

Book your free consultation now and let us show you what closing the gap could release.

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