Starting a contracting business in California is exciting — but the financial mistakes you make in the first year can haunt you for years to come. Most new contractors are experts in their trade but have never run a business before. They don’t know how to set up accounting, when to pay taxes, how to manage cash flow, or what records to keep. This guide gives new contractors in California a clear, practical roadmap to get your bookkeeping right from day one — before the mess starts.
Why Bookkeeping Matters From Day One
Many new contractors think they’ll deal with bookkeeping “once the business picks up.” This is one of the costliest mistakes in small business. Bookkeeping is easier and cheaper to set up correctly from the beginning than to clean up after years of chaos. Clean books from month one means you know your profit margins, you capture every tax deduction, you have financial statements when you need them for bonding or financing, and you’re never blindsided by a tax bill you didn’t see coming.
Step 1: Structure Your Business Correctly
Before you do any bookkeeping, choose the right legal structure for your business. Most contractors in California operate as a sole proprietor (no formal entity), an LLC (Limited Liability Company), or an S-Corporation. Here’s a quick breakdown.
A sole proprietorship is the simplest but offers no liability protection and pays self-employment tax on 100% of net profit. An LLC provides liability protection (separates business and personal assets) and can be taxed as a sole proprietor initially, then elect S-Corp status once profitable. An S-Corporation is the most tax-efficient structure for contractors earning $60,000+ in net profit, as it reduces self-employment taxes significantly through the owner-salary structure.
Whatever structure you choose, get an EIN (Employer Identification Number) from irs.gov — it’s free, takes 10 minutes, and you’ll need it for everything. Then open a dedicated business checking account at your bank using your EIN. Never mix personal and business funds — this is the most fundamental rule of business bookkeeping.
Step 2: Get Your CSLB License (If Not Already)
Operating as an unlicensed contractor in California is a serious risk. You cannot legally collect payment for work over $500, you’re exposed to significant fines, and you have no legal recourse for non-payment. Make sure your CSLB license is active and in good standing, your license bond ($25,000) is current, your workers’ comp certificate is on file with CSLB (if you have employees), and you’re registered with the DIR (Department of Industrial Relations) for public works projects if applicable.
Step 3: Set Up QuickBooks Online
QuickBooks Online is the right bookkeeping platform for contractors in California. Start with the Plus or Contractor plan to get access to Projects (job costing). Here’s what to set up on day one.
Chart of Accounts
Your Chart of Accounts is the backbone of your bookkeeping system. For a contractor, you need separate income accounts for each service type (residential, commercial, service calls), separate cost of goods sold accounts for labor, materials, subcontractors, and equipment, and clear overhead expense categories for insurance, vehicles, tools, marketing, and professional services. Don’t use the default QuickBooks setup — it’s generic and not designed for contractors. Work with a bookkeeper to create a contractor-specific Chart of Accounts.
Connect Your Bank Accounts
Connect your business checking account and business credit card to QuickBooks via the bank feed. This automatically imports transactions daily and dramatically reduces data entry. Review and categorize imported transactions weekly — don’t let them pile up.
Enable Job Costing
Turn on Projects in QuickBooks from the beginning. Create a project for every job — even small ones. Assign all income and expenses to the appropriate project. Over time, this data becomes invaluable for bidding and understanding your most profitable work types.
Step 4: Understand Your Tax Obligations as a New Contractor
New contractors are often shocked by their first tax bill. Here’s why: as a self-employed contractor, you pay both the employee and employer shares of FICA taxes (Social Security and Medicare) — a combined 15.3% on net self-employment income, in addition to federal and California income taxes. Your total effective tax rate as a profitable sole proprietor can easily be 35–45% of net profit.
The solution is estimated quarterly tax payments. The IRS and California FTB require you to pay taxes quarterly if you expect to owe $1,000 or more at year-end. Quarterly payment deadlines are April 15, June 15, September 15, and January 15. If you miss these payments, you’ll owe underpayment penalties on top of your tax bill.
From your very first payment received, set aside 30–35% in a dedicated tax savings account. Make this automatic — transfer it the same day the payment lands. Never touch this money for business operations.
Step 5: Track Every Business Expense
Every legitimate business expense is a tax deduction that reduces your taxable income. New contractors often miss thousands of dollars in deductions because they don’t track expenses systematically. Use a business credit card for all business purchases — this creates an automatic record. Take photos of all cash receipts with QuickBooks Mobile. Track business mileage with an app like MileIQ or QuickBooks mileage tracker. Keep all contractor-related expenses: CSLB fees, tools, work clothing, safety equipment, training, professional memberships, software subscriptions, and home office if applicable.
Step 6: Create a Simple Invoicing System
Invoice promptly — ideally the same day a job is completed or a milestone is reached. Use QuickBooks invoicing to send professional invoices by email. Include your CSLB license number on all invoices (required in California), clear payment terms (Net 15 or Net 30), and your contact information. Follow up on any unpaid invoice within 5 business days of the due date. Cash flow is king in a contracting business, and slow invoicing is the #1 self-inflicted cash flow problem.
Step 7: Hire a Bookkeeper Early
The most common advice new contractors ignore — and later regret — is to hire a bookkeeper before they feel they “need” one. A bookkeeper who specializes in contractors does more than categorize transactions: they set up your QuickBooks correctly, catch tax-saving opportunities, keep your books current so you always know your financial position, help you understand your numbers, prepare you for tax season, and flag problems before they become crises. The cost of monthly bookkeeping — typically $300–$800/month for a small contractor — pays for itself many times over in tax savings and avoided mistakes.
Frequently Asked Questions
Do I need an accountant and a bookkeeper?
For most new contractors, you need a bookkeeper (to maintain your monthly books) and a CPA (to prepare and file your annual tax return and provide strategic tax advice). These are different roles. A bookkeeper keeps your records current and clean. A CPA advises on tax strategy and files returns. Many small contractors use a bookkeeper year-round and a CPA at tax time.
What’s the first thing I should do for bookkeeping as a new contractor?
Open a dedicated business checking account with your EIN, get QuickBooks Online set up with a contractor-appropriate Chart of Accounts, and set up a tax savings account where you automatically move 30% of every payment received. These three steps alone will put you ahead of 80% of new contractors.
How do I know if I’m making a profit as a new contractor?
Run a Profit & Loss report in QuickBooks monthly. Track your revenue, your direct job costs (labor, materials, subs), and your overhead. The difference is your net profit. Also run the Project Profitability report for each completed job — this tells you exactly which jobs made money and by how much.
For more information, see our guide on choosing the right business structure.
For more information, see our guide on setting up QuickBooks from day one.
For more information, see our guide on CSLB financial record requirements.
For more information, see our guide on how much to set aside for taxes.
Start Your Contracting Business on the Right Financial Foot
Bookkeeping Champs specializes in helping new contractors in Los Angeles, Ventura County, and the San Fernando Valley set up QuickBooks correctly, establish clean financial systems, and build the bookkeeping foundation that supports long-term growth. Call (818) 679-4451 for your free new contractor consultation.
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