Resource Library / SOP 02 · Client Billing
Money · Full guide
Client Billing
Irregular billing is expensive twice: cash arrives unpredictably, and a client who receives four months of work in one invoice reads it as a surprise rather than a summary. This guide puts the cycle on a calendar and the narratives in plain language.
Process owner
Bookkeeper or billing admin
Reviewed by
Billing attorney
Applies to
Every fee-earning matter
Review cycle
Every 12 months
Section one
Why billing is a client-service process
Billing is usually filed under accounting. It belongs under client service. An invoice is the single document a client reads most carefully, often the only one they read line by line, and it arrives at the moment they are deciding whether the representation is worth what it costs.
When bills go out irregularly, two things happen. The firm cannot predict its own cash, so it makes staffing and spending decisions on guesswork. And the client receives a large, undifferentiated demand covering work they have partly forgotten, which converts a routine transaction into a negotiation.
Neither problem is about the amount charged. Firms with higher rates and disciplined billing have fewer fee disputes than firms with modest rates and erratic billing. Predictability and clarity are what clients are actually responding to.
The fix is unglamorous: a fixed monthly calendar, a standard for what a time entry must say, and a rule that nobody sends an invoice the client has not been prepared for.
Section two
Purpose and scope
Purpose
Produce accurate invoices on a predictable schedule, written so a client can understand what was done and why it was necessary, with any variance from an estimate raised before the work is performed rather than after.
In scope
Time capture, the monthly billing cycle, narrative standards, review and approval, delivery, and the mechanics of applying retainers and drawing against trust. Applies to hourly, flat-fee, and hybrid arrangements.
Out of scope
Setting rates and fee structures, which belong to the firm's fee policy. Pursuit of unpaid balances, which is covered by collections. Final billing at the end of a matter, which is covered by case closing. Trust account rules themselves, which are set by your jurisdiction.
Section three
The monthly cycle
Five dates, the same every month, published where everyone can see them. The point of fixing the dates is that no one has to decide when billing happens.
01
All timekeepers
Time entries complete — by the last business day
Every person who records time closes out the month by a stated day. Entries made weeks later are reconstructions: they lose detail, they under-record, and they are the main source of narratives a client cannot follow. Daily contemporaneous entry is the standard; the month-end date is the backstop, not the plan.
02
Bookkeeper
Draft invoices prepared — first two business days
Pull the month's entries, apply the correct rate and fee arrangement for each matter, add disbursements and costs with backup attached, apply retainers or trust draws, and flag anything unusual: a matter running well past estimate, a rate that looks wrong, an entry with no narrative.
03
Billing attorney
Attorney review — a fixed two- or three-day window
The responsible attorney reads every narrative on their matters as a client would. This is where entries get rewritten, where time that should not be charged gets written off, and where a bill that is going to shock someone gets a phone call attached to it. Review is not a formality and it cannot be delegated back to the bookkeeper.
04
Bookkeeper
Invoices issued — the same date every month
Finalize and send on a stated day, by the delivery method each client has agreed to. Clients should know, without asking, roughly when the firm's bill arrives. Include the payment terms, accepted methods, and a named person to contact with questions.
05
Bookkeeper
Reconcile and report — within three business days
Record what was billed, what was collected, what remains outstanding and for how long, and the current trust position for every matter. This report is what makes collections a routine rather than an emergency.
Section four
Writing a narrative a client can read
A time entry is a communication, not a bookkeeping code. Three rules cover almost every case.
State what was done and why it mattered to the matter. "Legal research" tells the client nothing. "Researched whether the notice requirement in the lease applies to a month-to-month tenancy, to determine whether the landlord's termination is defective" tells them what they bought.
Do not block-bill unrelated tasks into a single line. A 3.5-hour entry covering a call, two emails, a document review, and a drive is unreviewable by the client and, in many jurisdictions, difficult to defend if the fee is ever examined. Separate the tasks.
Write for a reader who does not know the vocabulary. Avoid internal shorthand, abbreviations only the firm uses, and case citations in a narrative where a plain description would do. The test is whether an intelligent person unfamiliar with litigation could read the line and understand what happened.
Two further habits save more disputes than any language choice. Write off time the client should not pay for, and say so on the invoice — a visible no-charge line buys enormous credit. And where work will exceed an estimate, call before doing it, not when billing it.
The test that matters
Before an invoice goes out, ask whether you would be comfortable reading it aloud to the client line by line. If any entry would need explaining, rewrite it now rather than defending it later.
Section five
Retainers, trust, and client funds
Handling client money is the strictest area a small firm operates in, and the consequences of getting it wrong are disciplinary rather than commercial. This section is deliberately conservative; your own jurisdiction's rules govern absolutely.
Keep it separate, always
Client funds live in a client trust account, never in the operating account, and never commingled with firm money. Earned fees are transferred out; unearned fees stay in. If you are unsure whether a fee is earned, treat it as unearned.
Draw only against a delivered invoice
Money moves out of trust after an invoice has been issued to the client covering the work, in the amount of that invoice, with the transfer recorded against the matter. No round-number draws, no advances against future work, no borrowing between matters.
Notify in writing
Every trust draw is reported to the client: what was applied, against which invoice, and the remaining balance. The invoice itself is the natural place to state it. A client should always be able to see their trust position without asking.
Replenish before you run out
Where the engagement provides for it, request replenishment when the balance falls below a stated threshold, in writing, with the projected work it covers. Requesting funds after the account is empty puts the firm in the position of working unpaid or stopping mid-matter.
Reconciliation is not optional
Trust accounts are reconciled on a schedule, typically monthly, against both the bank statement and the individual client ledgers — three-way reconciliation in most jurisdictions. Whoever performs it should not be the only person who reviews it. This is the single highest-risk area in small firm operations and the one most worth having a mentor look at with you.
Section six
Records and where they live
Name the actual system for each of these in your own version of the document.
Time entries
Recorded in the matter, contemporaneously, by the person who did the work
Draft invoice set
Kept with the review annotations, so write-offs are traceable
Issued invoices
Filed to the matter with the date and method of delivery recorded
Cost and disbursement backup
Receipts and invoices attached to the entry they support
Trust ledgers
One ledger per client matter, plus the account-level ledger
Monthly reconciliation
Signed or initialled, retained for the period your jurisdiction requires
Aged receivables report
Produced monthly, reviewed by the owner, drives collections
Estimate variance notices
Written notice to the client, filed with their response
Section seven
Where firms get this wrong
Six patterns, all of them common, none of them about the numbers.
Billing when there is time
Which means billing when work is slow, which is the month cash was already tight. The calendar exists to break that link.
Time entered from memory
Reconstruction under-records real work and produces narratives the client cannot follow. It costs the firm money and credibility at once.
Attorney review skipped
The bookkeeper sends what the system generated. Nobody has read the bill as a client would, and the first person to do so is the client.
No warning before a large bill
A surprise invoice is a dispute in the making. The call that precedes it takes five minutes and prevents most of them.
Trust treated casually
Round-number draws, transfers before invoicing, or a reconciliation nobody performs. This is the failure with disciplinary consequences, not just financial ones.
Nobody reads the aged report
Balances quietly pass sixty and ninety days. By the time anyone notices, the relationship has cooled and the money is much harder to collect.
Section eight
Adapting it to your firm
This is an educational example, not a form to adopt unread. Six decisions are yours.
Set your five dates. Entry deadline, draft date, review window, issue date, and reconciliation date. Publish them internally and hold to them for a full quarter before adjusting.
Decide your review discipline. Who reviews which matters, and what happens when the reviewer is in trial during the review window. Name the alternate.
Write your narrative examples. Take five weak entries from your own last billing run and rewrite them. Firm-specific examples teach far better than generic rules.
Set your estimate-variance trigger. A percentage or a dollar figure at which the client must be told before further work. Ten or twenty percent over estimate is a common threshold.
Confirm your trust rules. Read your own jurisdiction's trust accounting requirements directly, including reconciliation frequency, record retention, and any reporting obligation. Nothing here substitutes for that.
Handle flat fees explicitly. Decide when a flat fee is earned, how it is recorded, and what happens to the unearned portion if the matter ends early. This is a frequent source of trouble and it is entirely avoidable in writing.
Then run it for a full quarter before you change anything, because a billing cycle needs three iterations before you can tell what is a real problem and what was just the first month. The method is in the SOP development guide.
Next
Work through this with someone who has done it
Every attorney and law student who qualifies is paired with a free mentor: a firm owner, an operations expert, a finance expert, or a marketing expert. Bring this guide to the first call.
This guide is educational material published free of charge by the Law Firm Innovation Foundation, a 501(c)(3) nonprofit, EIN 42-2464496. It is not legal, ethical, tax, or accounting advice and does not create an attorney-client relationship. Professional conduct rules, trust accounting requirements, limitations periods, and procedural rules vary by jurisdiction; every reader is responsible for conforming their own practice to the authority that governs it. If you find an error or something incomplete for your jurisdiction, tell us and we will revise the page.