How to Choose a Business Structure

What Business Structure Options Exist

The IRS recognizes a handful of federal tax categories: sole proprietorship, partnership, corporation, and S corporation. States add the limited liability company (LLC) as a separate legal entity type, which the IRS then taxes as one of the categories above by default. Picking a structure means answering three questions: how many owners are there, how much liability protection do you need, and how do you want the business taxed.

Liability Protection

A sole proprietorship has no legal separation between the owner and the business, so the owner's personal assets, such as a home or savings, can be used to satisfy business debts or a lawsuit judgment. A general partnership works the same way for each partner, and each general partner can also be held responsible for the actions of the others.

An LLC and a corporation are both separate legal entities. In most instances, owners are not personally liable for the entity's debts beyond what they invested, as long as the business is run as a separate entity (keeping its own bank account, not mixing personal and business funds, and following its operating agreement or bylaws). A limited partnership or limited liability partnership can offer partial protection to some or all partners, depending on the partner's role.

Tax Treatment by Structure

A sole proprietorship reports business income on the owner's personal return (Schedule C) and pays self-employment tax on the profit. A partnership files an informational return and passes income through to each partner's personal return.

An LLC is, by default, taxed the same way: a single-member LLC is treated like a sole proprietorship and a multi-member LLC like a partnership, unless the LLC elects otherwise. A C corporation pays corporate income tax on its profits, and shareholders pay personal tax again on any dividends, which is commonly called double taxation. An S corporation election (available to an eligible LLC or corporation, made with IRS Form 2553) passes income through to the owners' personal returns like a partnership, while potentially letting owner-employees pay self-employment tax only on a reasonable salary rather than on all the profit.

Ownership and Control

A sole proprietorship has exactly one owner. A partnership needs at least two. An LLC can have one or more members and can be managed by its members directly or by an appointed manager, spelled out in an operating agreement. A corporation is owned by shareholders, directed by a board of directors, and run day to day by officers, which adds more required paperwork (bylaws, board resolutions, annual meetings) than an LLC typically needs.

An S corporation election caps ownership at 100 shareholders, and shareholders must generally be U.S. individuals, certain trusts, or estates, not other corporations or most LLCs. A C corporation has no ownership cap and can issue multiple classes of stock, which is why venture-backed companies usually form as C corporations.

Cost and Paperwork to Form Each

A sole proprietorship using the owner's own legal name typically requires no state formation filing, though a different business name usually needs a DBA ("doing business as") filing and some licenses may still apply. An LLC files Articles of Organization with the state; a corporation files Articles of Incorporation. State filing fees vary widely, from $35 in Montana to $500 in Massachusetts, and an EIN from the IRS is free regardless of structure. An LLC typically drafts an operating agreement (not usually filed with the state); a corporation adopts bylaws and holds an organizational board meeting, both of which add setup time a sole proprietorship or simple LLC does not need.

When to Change Structures Later

It is common to start as a sole proprietorship or single-member LLC while testing a business idea, then convert to a corporation once the business needs to raise money from investors, bring on a co-founder with equity, or offer employee stock options. Most states allow a statutory conversion from an LLC to a corporation through a filing with the Secretary of State, and the IRS treats an LLC's election to be taxed as a corporation (Form 8832) as a separate step from that state-level conversion. Because the paperwork and tax consequences of converting differ by state, talk to a tax professional before changing structures, especially if the business already has significant assets or contracts.

Industry Licensing Still Applies Regardless of Structure

Choosing an LLC or corporation does not replace the professional or industry license your state requires for fields like contracting, cosmetology, or financial services. Check your state's licensing board in addition to picking an entity type.

Single-Member vs. Multi-Member LLCs

A single-member LLC is simpler to run and is taxed like a sole proprietorship by default, but some states still require it to have a written operating agreement to prove the LLC is being treated as separate from its owner. A multi-member LLC needs an operating agreement that spells out how profits, losses, and decisions are split, since without one the state's default LLC statute controls instead.

Doing Business in More Than One State

If the business will operate in a state other than where it was formed, it generally needs to register there too, as a "foreign" LLC or corporation, which means an added filing fee and a registered agent in that state as well.

Operating Agreements and Bylaws Are Not Optional in Practice

Even though many states do not require an LLC to file an operating agreement, banks, courts, and co-owners rely on it to settle disputes over ownership percentage, voting, and what happens if a member leaves. A corporation's bylaws serve the same function and are typically expected before a corporate bank account can be opened.

Tax Elections Have Deadlines

An S corporation election generally must be filed with the IRS within a set window after the tax year starts (commonly two months and 15 days), so decide on tax treatment early rather than after the business has been running for months. A tax professional can confirm the deadline and whether the election makes sense given the business's expected profit.

This Is Not Legal or Tax Advice

Liability and tax outcomes depend on how a business is actually run, not just which box is checked on a state form. Talk to a tax professional or attorney before finalizing a structure, particularly if the business will have multiple owners, outside investors, or operations in several states.