Cash basis accounting is straightforward. You record revenue when money hits your bank account and expenses when money leaves it. If a consulting client pays you in March for work you did in February, March is when the revenue shows up on your books. If you pay your office rent on the first of the month, that’s when the expense is recorded.

Accrual accounting ties revenue and expenses to when they’re earned or incurred, regardless of when cash moves. You invoice a client in February for work completed that month, and February gets the revenue even if the check doesn’t arrive until March. You receive a bill from a subcontractor in December, and that expense hits December’s books even if you pay it in January.

For professional services firms like law practices, consultants, and other service-based businesses, the distinction matters more than it might seem. Professional services firms often have significant gaps between performing work, invoicing for it, and collecting payment. Under cash basis, a month where you completed $80,000 in billable work but only collected $30,000 from older invoices looks like a $30,000 revenue month. That’s misleading if you’re trying to understand how the business is performing right now.

Accrual gives you a real picture of profitability by matching revenue to the period when the work happened. It also forces you to track accounts receivable and accounts payable, which means you always know who owes you money and how long those invoices have been sitting unpaid. Aging reports become possible, and that visibility alone can improve your collections process significantly.

From a tax perspective, most professional services firms with less than $25 million in average annual gross receipts can choose either method. Cash basis can offer some tax timing advantages because you don’t owe taxes on revenue you haven’t collected yet. Some firms use cash basis for their tax return while running accrual-based reports internally for management decisions. That’s a perfectly valid approach and one worth discussing with your tax advisor.

If you’re just getting started or your firm is small with fast-paying clients and minimal outstanding invoices, cash basis might be fine for now. But as your firm grows and the lag between work performed and payment received widens, accrual becomes essential for making informed decisions about hiring, pricing, and cash flow. Working with experienced bookkeepers in Fairfax who understand your industry can help you set up the right method from the start and avoid a painful conversion later.

The bottom line is that cash basis tells you how much money moved. Accrual tells you how your business actually performed. For most professional services firms making decisions about growth and profitability, that distinction makes all the difference.