Entity Selection & Registration

Sole proprietorship: no separate legal entity — you and the business are the same for liability and tax purposes. Fastest and cheapest to start, but your personal assets aren't shielded from business debts or lawsuits.

LLC (Limited Liability Company): a separate legal entity that shields your personal assets in most circumstances, with flexible tax treatment (by default taxed like a sole prop/partnership, but can elect S-corp or C-corp tax treatment). The default choice for most first-time founders who want liability protection without corporate complexity.

S-corp: not actually a separate entity type — it's a tax election (an LLC or corporation can elect S-corp status) that can reduce self-employment tax once the business is profitable enough, in exchange for payroll requirements and more paperwork.

C-corp: a separate entity taxed independently from its owners (the "double taxation" people mention — the corporation pays tax, then shareholders pay tax again on dividends). Standard structure for businesses planning to raise venture capital or eventually go public.

Every state requires filing formation documents (commonly called Articles of Organization for an LLC, or Articles of Incorporation for a corporation) with the state's business filing agency, along with a filing fee that varies significantly by state.

Most states also require a registered agent — a person or company with a physical address in that state who can accept legal documents on the business's behalf. You can often be your own registered agent if you have a physical address in the state, or use a registered agent service for privacy and reliability (especially if you work from home and don't want your home address on public record).

A formation service (below) is generally fine for a straightforward single-owner or simple multi-owner LLC with no unusual complications.

Get an actual business attorney involved — not a formation service — if: you have multiple owners splitting equity in ways that need a real operating agreement, your business is built around intellectual property, or you're planning to raise money from investors. The cost of a lawyer up front is small compared to the cost of an ambiguous ownership agreement later.