Best Budgeting Method for Law Firms with Unpredictable Revenue

Executive Summary & Key Points

The Big Picture

Law firm revenue is rarely smooth. A contingency fee may create a large month followed by several quiet ones. Clients may pay invoices later than expected. A major case may settle sooner or later than planned. Even firms with strong annual revenue can feel cash-strapped when the timing of that revenue does not match the timing of their expenses.

That is why effective law firm budgeting should not rely on one fixed monthly revenue number. For many solo and small law firms, a better approach is to build the budget around conservative revenue expectations, known expenses, cash reserves, and clear rules for what happens when revenue is higher or lower than expected.

The Cheat Sheet

• Build your core budget around conservative revenue, not your best months.
• Separate fixed expenses from costs that can change as revenue changes.
• Keep enough operating cash to handle slower-than-normal months.
• Forecast cash flow separately from your profit and loss statement.
• Create a plan for strong months before the extra cash arrives.

The Business of Law: Your Revenue May Be Unpredictable, but Your Financial Plan Shouldn’t Be

Many law firm owners believe budgeting does not work for their firm because revenue changes too much.

That concern makes sense. A family law firm may have a steady flow of retainers but still experience changes in collections. A personal injury firm may wait months or years for a major case to resolve. An hourly firm can have strong billings one month and slower collections the next. Even flat-fee firms can experience seasonal changes in new matters.

The problem is not that budgeting does not work. The problem is often how the budget is built.

A traditional budget might assume the firm will generate $100,000 every month because annual revenue is expected to reach $1.2 million. But if actual monthly collections range from $60,000 to $150,000, that average does not tell the owner whether there will be enough cash for payroll next month.

A useful law firm budget has to account for timing.

Your rent, payroll, software subscriptions, insurance, loan payments, and other overhead continue whether collections are strong or weak. Taxes also need to be planned for. When these obligations are managed based on what is currently sitting in the bank account, one slow month can quickly create financial stress.

The goal of budgeting is not to perfectly predict what your firm will earn. It is to build a system that helps you make good decisions even when you cannot predict it.

Start With a Conservative Revenue Baseline

Why It Matters:

One of the biggest budgeting mistakes law firms make is building expenses around optimistic revenue. When a firm has a few strong months, it can be tempting to assume that level of revenue is the new normal.

With unpredictable revenue, your budget should begin with a number you can reasonably expect to collect, even during a slower period.

How It Works:

Start by reviewing at least the previous 12 months of actual collections. Depending on your practice area and the amount of revenue variation, looking at 18 to 24 months can provide even better context.

Look for:

• Your average monthly collections
• Your lowest revenue months
• Your highest revenue months
• Seasonal patterns
• Changes in case volume
• Changes in average matter value
• Large settlements or fees that made certain months unusual
• The difference between amounts billed and amounts actually collected

From there, create a conservative baseline for the firm’s regular operations.

For example, imagine a firm collected between $60,000 and $130,000 per month last year, with average monthly collections of $90,000. Building recurring expenses around $90,000 or $100,000 of monthly revenue could leave the firm vulnerable during slower periods.

Instead, management may decide that $70,000 represents a more reasonable baseline for its core budget. That does not mean the firm expects to earn only $70,000 every month. It means the firm wants its essential financial commitments to remain manageable when revenue is closer to that level.

CPA Pro Tip: Do not let one large settlement or unusually profitable month distort your baseline. Separate unusual revenue from recurring collections so you can see what the firm’s normal operations actually support.

Separate Fixed Expenses From Flexible Spending

Why It Matters:

Not every expense should be treated the same way. Some costs have to be paid every month. Others can be increased, delayed, or reduced depending on the firm’s financial position.

Knowing the difference gives you more control when revenue changes.

How It Works:

Start by separating expenses into two broad groups.

Fixed or essential expenses may include:

• Payroll and payroll taxes
• Rent
• Insurance
• Practice management software
• Accounting software
• Loan payments
• Core technology
• Required professional expenses

Then identify more flexible spending, such as:

• Optional advertising campaigns
• Certain travel
• New equipment
• Nonessential subscriptions
• Office upgrades
• Discretionary bonuses
• Some professional development expenses

This does not mean flexible expenses are bad. Marketing, hiring, technology, and professional development can all support growth.

The difference is that you know which costs can be adjusted if collections are temporarily below expectations.

You can also create thresholds for larger decisions. For example, instead of hiring another employee because the firm had two strong months, you might require collections to remain above a certain level for several months before adding another permanent salary.

This helps prevent temporary revenue spikes from creating permanent overhead.

CPA Pro Tip: Review recurring subscriptions at least once or twice a year. Small software charges can quietly become a significant expense as your firm grows and adds new tools.

Build a Cash Reserve Into Your Law Firm Budgeting System

Why It Matters:

A budget tells you how you plan to use money. A cash reserve gives you time when reality does not follow that plan.

For firms with unpredictable revenue, reserves are especially important because the timing of collections can change without much warning.

How It Works:

First, calculate the firm’s essential monthly operating expenses. Then determine how many months of those expenses you want available as a reserve.

There is no single reserve amount that works for every law firm. The appropriate level depends on factors such as:

• How predictable collections are
• Practice area
• Payroll size
• Debt obligations
• How quickly the firm can reduce expenses
• How concentrated revenue is among clients or matters
• The owner’s comfort with risk

A firm with highly predictable recurring revenue may be comfortable with a smaller reserve. A contingency-based firm with long gaps between major settlements may need substantially more.

The important part is treating the reserve as part of your financial system rather than simply leaving “whatever is left” in the checking account.

Set a reserve target and build toward it intentionally.

When a strong month occurs, part of the additional cash can replenish or increase reserves instead of immediately becoming owner distributions or new spending.

CPA Pro Tip: A large bank balance does not automatically mean you have excess cash. Some of that money may already be needed for payroll, taxes, upcoming bills, or other obligations. And client trust funds are never part of the firm’s operating reserve.

Use Rolling Cash Flow Forecasts Instead of Relying Only on an Annual Budget

Why It Matters:

An annual budget is useful for setting goals, but it can become outdated quickly when revenue is unpredictable.

A rolling cash flow forecast gives you a more current picture of what is likely to happen next.

How It Works:

Your forecast should look ahead and estimate expected cash coming in and cash going out.

Depending on your firm’s needs, you might maintain a 13-week cash flow forecast for short-term decisions while also keeping a longer monthly forecast for the rest of the year.

Your forecast may include:

Expected cash inflows:

• Expected invoice collections
• Retainer replenishments that will become earned fees
• Recurring payments
• Expected settlement fees
• Other operating revenue

Expected cash outflows:

• Payroll
• Rent
• Software
• Marketing
• Insurance
• Debt payments
• Taxes
• Owner distributions
• Planned hiring
• Equipment purchases
• Other significant expenses

Update the forecast as new information becomes available.

If a settlement is delayed, change the forecast. If collections are running ahead of expectations, update it. If you decide to hire someone, add the expected payroll cost before making the final decision.

The purpose is not to predict the exact bank balance 90 days from now. It is to identify potential cash shortages while there is still time to respond.

CPA Pro Tip: Do not confuse accounts receivable with cash. A client owing you $25,000 does not help fund payroll until that money is actually collected.

Create Rules for High-Revenue Months

Why It Matters:

Unpredictable revenue creates problems during slow months, but strong months can cause problems too.

When a large payment arrives, it is easy to see the additional bank balance as available money. Without a plan, that cash may quickly go toward owner distributions, hiring, equipment, or other spending.

Then taxes arrive. Or collections slow down.

A strong month should strengthen the firm’s financial position rather than create a new cash flow problem.

How It Works:

Decide in advance how excess cash will be handled.

A strong-month system might prioritize money in this order:

1. Cover current operating expenses.
2. Set aside funds for upcoming payroll and obligations.
3. Fund tax reserves based on current projections.
4. Replenish the firm’s operating reserve.
5. Fund planned investments.
6. Consider additional owner distributions after the other priorities are covered.

The exact order and percentages will depend on the firm.

The key is deciding before the money arrives.

This is especially useful for contingency fee firms. A large settlement may create a significant increase in income, but that does not necessarily mean the entire amount should be distributed immediately.

CPA Pro Tip: Large revenue events should trigger a tax projection. Your estimated tax needs may change significantly after a major settlement or unusually profitable quarter.

Review the Budget Against Actual Results Every Month

Why It Matters:

A budget becomes useful when you compare it with what actually happened.

If you create a budget in January and do not review it again until December, it cannot help you make decisions throughout the year.

Monthly review turns your budget into a management tool.

A reliable budget starts with reliable numbers. Following a consistent law firm month-end close process helps make sure your accounts are reconciled and your financial reports are accurate before you compare actual performance against your budget. 

How It Works:

After the books are closed each month, compare budgeted results with actual performance.

Review items such as:

• Revenue versus budget
• Collections versus billings
• Payroll costs
• Marketing expenses
• Operating expenses
• Profit margin
• Accounts receivable
• Cash balance
• Reserve balance
• Upcoming tax obligations

Then investigate meaningful differences.

If revenue missed the budget, ask why. Was billing lower? Were collections slower? Did fewer new matters come in?

If expenses were higher, determine whether the increase was temporary or likely to continue.

Your practice management and accounting systems can also help provide context. For firms using Clio and QuickBooks Online, properly maintained data can help connect operational activity with financial results.

The goal is not to criticize every difference between the budget and actual results. Variances are expected. The goal is to understand them and decide whether anything needs to change.

CPA Pro Tip: Clean monthly books matter. If your financial statements are several months behind, your budget comparison is also several months behind. By the time you identify a problem, your options may be more limited.

Commonly Missed Items in Law Firm Budgeting

A budget can look complete and still leave out expenses that create significant cash pressure later.

One common problem is budgeting only for expenses that occur every month. Annual, quarterly, and irregular costs still need to be funded.

Make sure your budget considers items such as:

• Annual malpractice insurance premiums
• Bar dues and professional memberships
• Quarterly estimated tax payments
• Annual software renewals
• Bonuses
• Equipment replacements
• Continuing legal education
• Recruiting and hiring costs
• Retirement plan contributions
• Business tax return preparation
• Planned marketing campaigns
• Debt principal payments
• Seasonal changes in payroll or staffing

Taxes deserve particular attention.

Profit and cash are not the same thing. A firm can have enough cash for current expenses while still failing to reserve enough for future taxes. As profitability changes, tax projections should be updated so estimated payments and cash reserves can be adjusted.

Owner distributions should also be planned instead of treated as whatever happens to be left in the account. When distributions are tied to current cash, reserves, tax obligations, and expected future expenses, owners can take money from the business with greater confidence.

Finally, keep trust accounting completely separate from this process. Client funds held in an IOLTA or other trust account are not operating cash and should never be included when calculating available reserves, profit distributions, or spending capacity. Proper trust accounting procedures and three-way reconciliations remain essential regardless of the firm’s cash position.

Frequently Asked Questions

The Bottom Line: Build a Budget That Can Handle the Unexpected

The best law firm budgeting system is not the one that predicts every dollar perfectly. That is rarely possible, especially when collections depend on settlements, client payments, retainers, or changing matter volume.

A better system gives you clear rules for different situations. You know what the firm needs to operate each month, how much cash you want in reserve, which expenses can be adjusted, and what you will do when revenue comes in above or below expectations.

That information also supports better tax planning. When your accounting, cash flow forecast, budget, and tax strategy work together, you can make decisions based on the firm’s full financial picture instead of the current bank balance.

For a growing law firm, that can mean knowing when you can afford to hire, how much you can safely distribute, whether you have enough cash for a slower quarter, and when a change in profitability should trigger a new tax projection.

You cannot control exactly when every dollar will arrive. You can control the financial system you build around it.

Ready to Build a Better Financial Plan for Your Law Firm?

Aligned CPA works exclusively with solo and small law firms that want better visibility into their numbers. We help law firm owners improve their bookkeeping, financial reporting, cash flow planning, tax strategy, and overall financial systems so they can make informed decisions as their firms grow.

If unpredictable revenue makes it difficult to know what you can spend, save, or distribute, schedule a discovery meeting with Aligned CPA to see how we can help.