Legal accounting for law firms rests on one rule that shapes everything else: money belonging to clients has to stay separate from money belonging to the firm. Around that rule sits a set of practical obligations — a trust account governed by state bar rules, disciplined transfers into the operating account as fees are earned, regular three-way reconciliations, federal reporting for large cash payments and vendor fees, and record retention that will hold up in an audit. Get those pieces right and the firm’s finances stay defensible. Get them wrong and the consequences run from restitution and fines to suspension or disbarment.
Keep Client Money in a Separate Trust Account
A client trust account holds money that doesn’t belong to the firm: unearned retainers, settlement proceeds awaiting distribution, and funds set aside for court costs. Rule 1.15 of the ABA Model Rules of Professional Conduct requires lawyers to keep those funds in a separate account from their own, with only one narrow exception — the lawyer may deposit personal funds into trust to cover bank service charges on the account itself.1American Bar Association. Rule 1.15 – Safekeeping Property
Mixing client funds with firm money is commingling, and it’s one of the fastest routes to discipline. Depending on severity and intent, consequences range from mandatory restitution and license suspension to civil liability for breach of fiduciary duty, disbarment, and criminal fraud charges. Regulators don’t distinguish between carelessness and intent when client money goes missing; even accidental commingling gets investigated.
When a firm receives money on behalf of a client, the entire amount goes into trust first. A $100,000 settlement check must be deposited into trust before anyone takes a cut. Only after the check clears and the lawyer calculates the earned portion can the firm move its fees to the operating account and disburse the client’s share.1American Bar Association. Rule 1.15 – Safekeeping Property Payments to medical providers, co-counsel, and other third parties with a claim on the funds also flow out of trust, so every dollar has a documented path.
How IOLTA Fits In
When client funds are too small or held too briefly to earn meaningful interest for an individual client, they get pooled in an Interest on Lawyers’ Trust Account. All 50 states and the District of Columbia require IOLTA participation. The bank forwards interest on the pooled balance to the state’s IOLTA program, which distributes the money to legal aid organizations and pro bono programs serving low-income residents.2National Association of IOLTA Programs. IOLTA Basics
Larger deposits or funds held long enough that the interest would matter to the client go into a separate individual trust account instead of the IOLTA pool.
Overdraft Notification
Banks that hold lawyer trust accounts must agree to notify the state disciplinary agency any time a properly payable instrument is presented against a trust account with insufficient funds, whether or not the bank honors the check.3American Bar Association. Model Rules for Trust Account Overdraft Notification – Rule 2 The bank simply reports; the disciplinary agency decides whether to investigate. Firms that don’t maintain their trust accounts at an approved institution risk losing the ability to hold client funds at all.
Move Money to the Operating Account Only When Earned
The operating account is where the firm’s own money lives. Rent, payroll, software, insurance — every business expense comes out of this account. Money enters it only after the firm has legitimately earned it by performing legal work or hitting a billing milestone.
The transfer from trust to operating is the critical moment in law firm accounting. When a lawyer bills three hours of research at $300 an hour, that $900 moves from trust to operating only after the hours are documented and invoiced. Before that transfer, the money still belongs to the client. Firms that spend from trust before earning the fees are borrowing client funds without permission, which is a commingling violation even if the firm plans to “pay it back” from the next deposit.
Earned Versus Unearned Fees
Rule 1.15 requires lawyers to deposit advance fees into the client trust account and withdraw them only as earned or as expenses are incurred.1American Bar Association. Rule 1.15 – Safekeeping Property The line gets tricky with electronic payments. When a client pays by credit card and the processor can’t split earned and unearned amounts, the safe practice is to deposit the whole payment into trust and promptly transfer the earned portion to operating. Getting this wrong, even through a processor’s default settings, creates an ethical problem.
Cash Reserves
Beyond the trust-to-operating discipline, healthy firms keep a cash reserve in the operating account so slow months don’t create pressure to dip into trust. The general benchmark is three to six months of operating expenses. Contingency-fee practices with unpredictable cash flow lean toward the higher end; firms with steady retainer-based income can usually operate at the lower end. Start with fixed monthly overhead — rent, payroll, subscriptions — and add a buffer for variable costs.
Billing Rules That Feed the Books
Revenue for most firms starts with documented time entries. The standard billing increment is one-tenth of an hour, or six minutes. A 14-minute phone call logs as 0.3 hours. Vague or bundled entries are the most common source of fee disputes with clients, so granularity is worth the effort.
Three fee structures cover most practices:
- Hourly billing: the firm charges for each recorded increment. Rates vary by attorney experience and market.
- Flat fees: a set price for a defined scope of work, common for routine matters like uncontested divorces or simple wills.
- Contingency fees: the firm takes a percentage of any recovery, typically 33 to 40 percent, and collects nothing if the client loses. Contingency agreements must be in writing, signed by the client, and must spell out the fee percentage at each stage (settlement, trial, appeal) along with how expenses are handled.4American Bar Association. Rule 1.5 – Fees
Whatever the billing method, the Model Rules prohibit unreasonable fees. Reasonableness turns on factors like the time and skill required, the result obtained, the customary rate for similar work in the area, and the lawyer’s experience.4American Bar Association. Rule 1.5 – Fees A lawyer who bills ten hours for a task any competent attorney could finish in two will struggle to defend it.
Evergreen Retainers
An evergreen retainer requires the client to top up the trust balance whenever it drops below a set minimum. The initial deposit sits in trust; as the attorney bills, earned fees move to operating; when the balance hits the threshold, the client gets a replenishment notice. The agreement should define the trigger amount, the timeline for the client to respond, and what happens if they don’t pay, including whether the firm can pause work. Invoices should show starting and ending retainer balances so the client always knows where things stand.
Watch Processing Fees on Card Payments
Accepting cards creates a specific trap. A standard processor charges two to three percent per transaction and deducts that fee from the deposit. If a client sends $1,000 toward a trust balance, the firm may receive only $970 after the processor’s cut. That missing $30 is the firm’s cost of doing business, not the client’s, and it can’t come out of trust. The firm must cover the difference from operating to keep the trust balance whole.5American Bar Association. The Ultimate Guide to Legal Payments
General-purpose platforms like PayPal or Venmo make this separation difficult because they don’t route earned and unearned fees to different accounts. Legal-specific processors are designed to split payments at the point of transaction, sending unearned fees to trust and earned fees to operating while keeping the processing fee out of trust entirely.6American Bar Association. A Guide to Ensuring IOLTA Account Compliance Firms using generic processors need to watch every transaction to make sure trust funds aren’t being quietly reduced by merchant fees.
Passing the processing fee along to the client as a surcharge raises its own issues. Several jurisdictions prohibit lawyers from adding charges beyond the agreed-upon rate when a client pays by card. Check your state bar’s current guidance before adding a convenience fee.
Federal Tax Reporting
Law firms handle enough cash and settlement money to trigger federal reporting requirements many other businesses never see. The penalties compound quickly.
Form 8300 for Cash Over $10,000
Any business that receives more than $10,000 in cash from a single transaction or related transactions must file IRS Form 8300 within 15 days of receiving the payment.7Internal Revenue Service. Form 8300 and Reporting Cash Payments of Over $10,000 Law firms are explicitly covered because legal services qualify as a trade or business.8Internal Revenue Service. Instructions for Form 8300 The firm also has to send a written statement to each person named on the form by January 31 of the following year.
Civil penalties start at $60 per return if corrected within 30 days but jump to $310 per return for negligent failures. Intentional disregard carries a penalty of the greater of $31,520 or the amount of cash received in the transaction, up to $126,000. Willfully failing to file is a felony punishable by a fine of up to $25,000.9Internal Revenue Service. IRS Form 8300 Reference Guide
Form 1099 for Payments of $600 or More
Firms that pay $600 or more to expert witnesses, investigators, co-counsel, or other service providers during a year must report those payments on Form 1099. One detail catches firms off guard: payments to lawyers and law firms must be reported on a 1099 regardless of whether the recipient is incorporated, which overrides the general rule that payments to corporations don’t require reporting.
Settlement distributions follow different rules. The settling defendant, not the law firm, typically bears the obligation to issue the 1099. But when a lawyer exercises management and oversight of client funds, the firm may also have reporting obligations when distributing them. Settlements for personal physical injuries are generally tax-free to the recipient, so no 1099 is required for those.
For the 2026 tax year, penalties for failing to file correct information returns are $60 per form if corrected within 30 days, $130 per form if corrected by August 1, and $340 per form after that. Intentional disregard doubles the penalty to $680 per form.10Internal Revenue Service. Information Return Penalties Penalties apply per form, so a firm that misses ten 1099s filed after August 1 faces $3,400 before anyone even asks whether the failures were intentional.
Three-Way Reconciliation
The most important internal check in law firm accounting is the three-way reconciliation, which compares three records that should always agree:
- The bank statement: what the bank says is in the trust account.
- The firm’s trust ledger: the master record of all deposits and withdrawals across the entire trust account.
- The individual client ledgers: the running balance for each client whose money is in the account, which should add up to the trust ledger total.
When all three match, every dollar in trust is accounted for and properly allocated. When they don’t, something has gone wrong: a deposit credited to the wrong client, a transfer that wasn’t recorded, or money that left the account without authorization. The ABA’s Model Rule on Financial Recordkeeping requires reconciliations at least quarterly, with copies retained.11American Bar Association. Model Rule on Financial Recordkeeping – Preface Many firms reconcile monthly because waiting a full quarter to find a discrepancy means three months of transactions to untangle.
A discrepancy of even a few cents demands investigation. It might be a rounding error, or it might be the first sign of a larger problem. Regulators care that it exists and that the firm didn’t catch it, not how big it is.
Records to Keep and for How Long
The ABA Model Rule on Financial Recordkeeping sets a floor of five years after the representation ends for the following records:
- Journals: deposit and disbursement records for every bank account, with dates, sources, payees, and descriptions.
- Client ledgers: individual records showing the source, amount, and disposition of every dollar held for each client.
- Fee agreements: copies of retainer and compensation agreements.
- Accountings: records showing how funds were disbursed to or on behalf of clients.
- Bills and expenses: copies of every invoice sent.
- Bank records: check registers, bank statements, deposit records, and canceled checks.
- Reconciliations: copies of trial balances and trust account reconciliations.11American Bar Association. Model Rule on Financial Recordkeeping – Preface
Some states extend the floor to six or seven years. Failing to produce these records during a bar audit doesn’t just result in fines; it shifts the burden to the firm to prove it handled client money properly, and that’s a much harder position to argue from.
Most firms now store financial records digitally. Cloud backups should use strong encryption for data at rest and in transit, and encryption keys should be stored separately from the data they protect and rotated regularly. Maintain multiple copies across different storage media, with at least one off-site and one immutable copy that can’t be altered or deleted.
Internal Controls and Audit Red Flags
Trust account audits don’t always announce themselves. Bar associations may open a review based on a bank overdraft notification, a client complaint, or random selection. The firms that pass without trouble are the ones that operate as if an audit could arrive tomorrow.
The most effective internal control is simple: no single person should be able to initiate, approve, and record a financial transaction. One person enters the bill, another approves the payment, a third handles reconciliation. In a solo practice where full separation isn’t practical, the lawyer needs compensating checks — reviewing bank statements personally, using software that creates an uneditable audit trail, and having an outside bookkeeper perform the reconciliation.
Common red flags that draw regulatory attention include trust balances that don’t match client ledger totals, unexplained transfers between trust and operating, and checks written to “cash” from the trust account. Watch for subtler indicators too: client ledgers showing negative balances (the firm spent more than that client had in trust), large round-number transfers without supporting documentation, and gaps in the check sequence.
Cash or Accrual Accounting
Most law firms use cash-basis accounting, recognizing income when payment arrives and expenses when bills are paid. Cash basis is simpler, aligns with how trust-to-operating transfers work, and is available to any firm whose average annual gross receipts over the prior three tax years stay below roughly $27 million. Firms above that threshold generally must switch to accrual-basis accounting, which recognizes revenue when earned and expenses when incurred regardless of when cash changes hands. The transition triggers a one-time tax adjustment that needs careful planning.
Even firms that file taxes on a cash basis sometimes track finances internally on an accrual basis for better management reporting. Knowing what’s been earned but not yet collected gives a clearer picture of financial health than the bank balance alone. The choice doesn’t affect trust account obligations. Those rules apply regardless of accounting method.