Law Firm Bookkeeping: IOLTA, Three-Way Reconciliation and Trust Rules
Most bookkeeping mistakes cost money. In a law firm, one category of mistake costs your licence.
Client trust accounting is regulated by your state bar, not by the IRS, and the penalties for getting it wrong run through the disciplinary system. That single fact should drive how a firm hires for this work.
The two sets of books
Every law firm runs two financially distinct things.
Operating funds are the firm's own money: earned fees, salaries, rent, software. These behave like any professional services business.
Trust funds are client money the firm is holding: retainers not yet earned, settlement proceeds, funds for filing fees. This money is never the firm's, sits in a separate account, and is tracked per client.
The bright line between them is the whole discipline. Money moves from trust to operating only when it has actually been earned, and that movement has to be documented.
IOLTA
IOLTA — Interest on Lawyers' Trust Accounts — is the mechanism for pooled client funds that are small in amount or short in duration. Interest earned goes to a state fund that typically pays for legal aid, not to the firm and not to the client.
Funds large enough or held long enough to earn meaningful net interest go in a separate client-specific account instead, with interest to that client. Where the line falls is a judgement call your state bar has rules about.
The rules that matter in practice:
- Never commingle. Firm money does not sit in trust; client money does not sit in operating. Depositing your own funds to cover bank fees is a violation in most states unless a small explicit cushion is permitted.
- Never overdraw a client's ledger. The firm may hold $80,000 in trust across thirty clients, but if one client's balance is $500 you cannot disburse $600 on their matter. You would be spending another client's money.
- Earn before you move. A retainer is the client's money until work is done against it. Moving it early is a violation even if you later do the work.
- Reconcile monthly, three ways.
Three-way reconciliation
The core control, and the thing an auditor asks for first. Three numbers must agree every month:
- The bank statement balance for the trust account.
- The book balance for the trust account.
- The sum of all individual client ledger balances.
Two out of three is a red flag. Bank and book agreeing while the client ledgers sum to something different means the total is right but the allocation between clients is wrong — which is exactly the condition under which one client's money funds another's matter.
Most state bars require this monthly, require the records be kept for years after a matter closes, and require the firm produce them on demand. Many jurisdictions also require the bank to notify the bar directly if a trust account is ever overdrawn, which means the regulator can find out before you do.
Cash versus accrual
Most small law firms report on cash basis for tax, which is generally permitted for personal service businesses regardless of size.
Cash basis makes trust discipline more important, not less, because trust money in the bank looks like cash. A firm that watches its bank balance rather than its operating balance will feel rich while holding money it does not own. Report on trust and operating separately, always.
What the market looks like
We profile 123 US accounting firms naming law firms as an industry they serve:
- 92 offer bookkeeping
- 59 offer tax preparation
- 43 offer payroll
- 39 offer tax planning
- 24 offer fractional CFO services — a high share for such a small pool, reflecting partner compensation and profitability work
- 22 state they work remotely
- 25 name QuickBooks
That total of 123 is the number to notice. It is one of the smaller industry pools in our dataset — far smaller than construction (567) or real estate (614) — despite law firms being numerous and having unusually specific requirements. The specialist supply here is thin, which is an argument for filtering hard rather than hoping a generalist picks it up.
What it costs
- Monthly bookkeeping with trust reconciliation: commonly $500 to $1,500 a month for a small firm, with the trust work being the premium over ordinary bookkeeping.
- Trust account clean-up: priced as a project, and it can be substantial if client ledgers have to be reconstructed.
- Practice management software: Clio, PracticePanther and similar handle client ledgers and sync to a general ledger. Budget for the integration, and ask who owns it.
Questions to ask a firm
- Have you run three-way trust reconciliations, and in which states?
- What do you do if the reconciliation does not balance — who is told, and when?
- Do you know my state bar's specific trust record retention requirement?
- Which practice management systems have you integrated with a general ledger?
- Who reviews the trust reconciliation — the person who prepared it, or someone else?
The last one matters. Separation between preparer and reviewer is basic internal control, and in a two-person bookkeeping shop it may not exist.
One caution worth stating plainly: the ethical responsibility for a trust account sits with the lawyer, not the bookkeeper. Delegating the work does not delegate the duty. Review the monthly reconciliation yourself.
Compare firms serving law firms: law firm bookkeeping, law firm payroll, or law firm fractional CFO.
Figures from the AccountingNearYou dataset, 13 August 2026. Trust accounting rules are set by each state bar and differ meaningfully between states; confirm your own jurisdiction's requirements rather than relying on a general summary.