How to Start a Solo Law Firm: Costs and Billing

To start a law firm as a solo, you need four things in place before the first client signs: an entity and bar registration that fit your state's rules, a properly set up client trust account, a written fee agreement for each billing model you plan to use, and a billing system that turns your time into collected cash. The legal work you already know how to do. The business side is where new firms struggle, so this guide focuses on costs, trust accounting, fee structures, collection benchmarks and a realistic first-year budget.

This article is general information, not legal or ethics advice. Professional conduct rules vary by state; check your state bar's rules and ethics hotline for your situation.

Step by step: how to start a law firm

1. Pick a practice area and market. Narrow beats broad. "Estate planning for small business owners in Tampa" is easier to market than "general practice".
2. Choose an entity. Many solos use a professional LLC or professional corporation; some states have specific rules for law firm entities and names. See LLC vs sole proprietorship.
3. Register with the bar as required, and check firm name and advertising rules.
4. Open bank accounts: an operating account and a client trust (IOLTA) account.
5. Buy malpractice insurance and general business coverage.
6. Set up practice management software for conflicts, calendaring, time tracking, trust ledgers and billing.
7. Draft fee agreements for hourly, flat fee and, where relevant, contingency matters.
8. Build a website and directory listings, then start networking for referrals.

How much does it cost to start a law firm?

The biggest cost decision is whether you need a dedicated office. Many solos start virtual and use shared conference rooms for client meetings. The figures below are illustrative first-year costs.

Item	Lean virtual practice	Office-based practice
Bar dues, registration, CLE	$800	$1,500
Entity formation and registered agent	$300	$800
Malpractice insurance (new solo)	$1,000	$3,000
Practice management and billing software	$1,200	$2,400
Legal research subscription	$1,200	$4,000
Website, domain, email	$1,000	$5,000
Computer, scanner, phone	$2,000	$4,000
Office rent or virtual office	$1,800	$24,000
Marketing and advertising	$2,000	$12,000
Part-time assistant	$0	$20,000
Total first year	$11,300	$76,700

Also plan for personal living costs. Most solos take several months to reach steady revenue, so a cash reserve of three to six months of expenses is wise. Our guide to a business emergency fund explains how to size it.

Trust accounting: the rule you cannot get wrong

ABA Model Rule 1.15, adopted in some form in every state, requires lawyers to hold client property separately from their own, keep complete records, and promptly deliver funds clients are entitled to. Your state bar publishes its own version of the rule, often with a trust accounting handbook. In practice:

• Advance deposits (often called retainers) for future hourly work go into trust and move to operating only after you earn the fee and bill it.
• Nominal or short-term funds go into an IOLTA account, where interest funds legal aid programs.
• Keep a ledger for each client, a general trust ledger and bank statements, and do a three-way reconciliation monthly.
• Never commingle. Do not pay office expenses from trust, and do not leave earned fees in trust indefinitely.
• Flat fees are treated differently by state. Some states let you treat a flat fee as earned on receipt if the agreement says so; others require trust until earned.

Billing ties directly to trust. When you invoice against a deposit, the invoice should show the work, the amount applied from trust, and the remaining trust balance. Our guide to retainer invoices shows how to lay that out.

Fee agreements and billing models

Model Rule 1.5 requires fees to be reasonable and generally requires the basis of the fee to be communicated, preferably in writing; contingency fee agreements must be in writing and signed by the client. Most solos put every engagement in a signed letter regardless.

Model	Works best for	Cash flow	Billing tip
Hourly	Litigation, ongoing advice	Monthly, depends on collections	Take an advance deposit and replenish it
Flat fee	Wills, trademarks, formations, uncontested matters	Upfront or staged	Define scope and what costs extra
Contingency	Personal injury, some employment cases	Lumpy; paid at resolution	Needs savings to carry costs for months
Subscription	Outside general counsel for small businesses	Recurring and predictable	Spell out included hours and response times
Limited scope	Document review, coaching self-represented clients	Upfront	Follow your state's limited-scope rule

Law firm billing benchmarks

Clio's Legal Trends benchmarks for 2025 put average utilization at about 38% of an eight-hour day (around 3 billable hours), realization at 88% and collection at 93% (Clio law firm benchmarks). In plain terms, out of every 8 hours worked, only about 2.6 hours are invoiced, and about 7% of what is invoiced never gets paid. That gap is why billing habits matter as much as rates.

Habits that close the gap:

• Record time daily, not at month-end.
• Write clear task descriptions that show value, not just "research".
• Invoice on the same day every month, and invoice flat fees at milestones.
• Offer card and ACH payments with an online link.
• Follow up on balances at 15, 30 and 45 days; see payment reminder emails for wording.

Worked example: a solo's first-year numbers

Priya opens a virtual estate planning and small business practice at $275 an hour and flat fees for common packages. Figures are illustrative.

Line	Amount
Flat-fee estate plans: 60 x $2,200	$132,000
Business formations and contracts: 40 x $1,200	$48,000
Hourly advisory work: 220 hours x $275 billed	$60,500
Less uncollected (7% of hourly billings)	($4,235)
Collected revenue	$236,265
Operating costs (lean budget plus more marketing)	($24,000)
Part-time paralegal (second half of year)	($18,000)
Profit before tax	$194,265

The example assumes a full pipeline, which takes time. A more cautious plan would model months one to six at a third of this volume. Notice that flat fees drive most of the revenue: they are paid upfront, have no realization gap, and are easier to market. Use our legal invoice template for hourly matters and a simple package invoice for flat fees.

What a law firm invoice should include

• Firm name, address, and the client and matter name or number
• Billing period and invoice number; our invoice number generator helps keep a consistent format
• Itemized time entries: date, timekeeper, description, hours, rate and amount
• Expenses and costs advanced, such as filing fees and courier charges
• Payments received and amounts applied from trust, with the remaining trust balance
• Total due, due date and accepted payment methods

Some corporate clients require LEDES electronic billing with task codes; ask during intake.

Marketing a new law practice

Most solos get their first clients from people they already know: former colleagues, classmates, other lawyers who need someone to refer conflicts or out-of-scope matters to, and accountants, financial planners and real estate agents who serve the same clients. Tell them exactly what you do and who you want to help. A specific message, such as "I handle trademark filings for small product brands", is easier to remember and pass on.

Online, focus on a few channels done well:

• A simple, fast website with practice area pages, fee information where you can share it, and a clear way to book a consultation.
• A Google Business Profile with accurate categories, hours and photos, and a steady flow of client reviews, subject to your state's rules on testimonials and advertising.
• Bar referral services and directories relevant to your practice area.
• Useful content that answers the questions clients ask at the first meeting.

Lawyer advertising rules vary by state and can restrict testimonials, claims about results and the word "specialist". Check your state's version of Model Rules 7.1 to 7.3 before launching ads.

Paid consultations vs free consultations

Many solos charge a flat consultation fee, often credited toward the engagement if the client hires them. It filters out tire-kickers and pays for your time. Others offer short free calls to qualify leads and then quote a fee. Either way, collect payment for paid consultations at booking, and state your invoice payment terms in every engagement letter.

Common mistakes new solos make

• Depositing an advance fee into the operating account. The most dangerous mistake in this list.
• No conflict check system from day one.
• Taking any case that walks in. It weakens your marketing and can strain competence.
• Billing quarterly or "when I get to it". Old invoices collect worse.
• No written scope. Scope creep on flat fees quietly erases profit.
• Ignoring reviews and local search. Clients look up lawyers on Google first. Our local SEO checklist covers the basics.

What to do when a client stops paying

Pause new non-urgent work, send a polite but firm reminder, and offer a payment plan. Check your fee agreement and state rules on withdrawal before stopping work on an active matter, especially in litigation where court permission may be required. Fee disputes may be eligible for your bar's fee arbitration program. For process ideas, see what to do when a client is not paying an invoice.

For flat-fee packages, consultation fees or simple matters where you do not need full practice management software, you can create a clean, itemized invoice with our free invoice generator - no sign-up required, and you can download it as a PDF to send to the client.