First-Time Business Owner: Tax Planning, Entity Selection, and Year-One Decisions

First-time business owners face critical tax decisions that set the trajectory for years to come. Entity selection, self-employment tax exposure, and bookkeeping foundations deserve expert guidance early to avoid costly mistakes.

The big planning areas:

• Entity selection. Sole proprietorship, LLC, S corp, or C corp each carry different tax rates, self-employment tax exposure, and administrative burden. The wrong choice costs money every year until you restructure -- which itself triggers tax consequences.
• Self-employment tax. As a business owner, you pay both the employer and employee portions of Social Security and Medicare taxes: 15.3% on net self-employment income up to the Social Security wage base, plus 2.9% on income above it. This surprises nearly every first-time owner.
• Estimated quarterly payments. There is no employer withholding taxes for you anymore. You must make quarterly estimated payments (Form 1040-ES) or face underpayment penalties under Section 6654.
• Bookkeeping requirements. The IRS requires adequate records to substantiate every deduction. Commingling personal and business accounts is the fastest way to lose deductions in an audit.
• Deduction opportunities. Home office (Section 280A), startup costs (Section 195), vehicle expenses, health insurance premiums, and retirement plan contributions (SEP-IRA, Solo 401(k)) are commonly missed by first-time owners.

What a CPA does for first-time owners: They set up the entity correctly, establish a bookkeeping system, calculate estimated payments, and identify deductions you did not know existed. A generalist accountant files what you give them; a business-oriented CPA builds the tax infrastructure that minimizes your liability from year one.

The tradeoff: The first year is when mistakes are cheapest to fix and most expensive to ignore. Paying for proper setup now avoids restructuring costs, missed deductions, and IRS penalties that compound every year you operate under the wrong structure.