To know what type of corporation you have, check three sources in order: the articles of incorporation filed when the business was created, the state’s business entity database where that filing lives, and the federal tax return the company files each year. The first tells you the legal structure the company was organized under. The second confirms how the state currently classifies it. The third reveals how the IRS taxes it, which is a separate question and doesn’t always line up with the first two. Read all three and the picture is complete.
Start With the Articles of Incorporation
The articles of incorporation are the founding document, and they carry the clearest signals. Look first at the corporate name. States require a designator such as “Incorporated,” “Corporation,” “Inc.,” or “Corp.” to identify the entity as a corporation. A name ending in “PC” or “Professional Corporation” tells you the business was formed by licensed professionals — doctors, lawyers, accountants — and operates under rules tied to that profession.
Next, read the purpose clause. A general business corporation usually states a broad purpose like “any lawful business activity.” A nonprofit’s articles read differently: they must dedicate the organization to charitable, educational, religious, or scientific purposes, and they must include a dissolution clause sending assets to another exempt organization if the entity shuts down. The IRS requires those provisions for any organization seeking tax-exempt status under Section 501(c)(3).1Internal Revenue Service. Does the Organizing Document Contain the Dissolution Provision Required Under Section 501(c)(3) Language like that is a nonprofit.
The bylaws add operational context. Standard business corporations have bylaws describing a board of directors, officer positions, and meeting procedures. Bylaws that let shareholders manage the company directly, without a formal board, or that restrict who can buy shares, point to a close corporation, designed for a small, tightly held group of owners. Bylaws referencing a public benefit purpose or requiring annual benefit reports on social or environmental impact point to a benefit corporation.
Stock certificates carry one more clue. Check the back for transfer restrictions. A certificate saying shares cannot be sold to outsiders without shareholder approval is a hallmark of a close corporation. Nonprofit corporations don’t issue stock at all, so an empty stock ledger is itself an indicator.
Search Your State’s Business Entity Database
When the internal records are missing or unclear, the state’s official record settles the question. Every Secretary of State office maintains an online business entity search. Enter the exact legal name or the state entity ID number and the database returns a summary with the entity type, formation date, and current standing. The field you want is usually labeled “Entity Type” or “Organization Type.” It will read something like “Domestic Business Corporation,” “Domestic Nonprofit Corporation,” “Close Corporation,” or “Professional Corporation.”
The record also shows whether the corporation is active, inactive, or administratively dissolved. If the entity was formed in a different state but is registered to do business in yours, it’s operating under foreign qualification. That doesn’t mean the company is international. It means it was incorporated elsewhere, and the state of original formation is the one whose laws govern its internal structure.
For a formal answer you can hand to a bank or a business partner, request a certificate of good standing, sometimes called a certificate of existence or certificate of status. It confirms the corporation’s legal existence, its type, and whether filings and fees are current. You can also order certified copies of the original formation filings — government-stamped reproductions of the articles as filed. Both carry modest state fees.
Check Which Tax Return the Company Files
State classification tells you the legal structure. The federal tax return tells you how the IRS actually treats the company. These are two separate systems, and a corporation can look one way in state records and another way on its tax return.
Form 1120: C-Corporation
A company filing Form 1120 is taxed as a C-corporation. This is the default classification for any corporation that hasn’t elected otherwise.2Internal Revenue Service. About Form 1120, U.S. Corporation Income Tax Return The corporation pays income tax on its earnings, and shareholders pay tax again on dividends when those earnings are distributed. That double layer of taxation is the defining feature of C-corporation status.
Form 1120-S: S-Corporation
A company filing Form 1120-S is an S-corporation. It pays no federal income tax at the entity level; income and losses pass through to shareholders’ personal returns and are taxed once.3Internal Revenue Service. Instructions for Form 1120-S, U.S. Income Tax Return for an S Corporation S status is not automatic. Someone had to file Form 2553 with the IRS to elect it.4Internal Revenue Service. Form 2553, Election by a Small Business Corporation If that form was never filed and accepted, the corporation is a C-corporation by default, regardless of what anyone assumed.
Form 990: Tax-Exempt Nonprofit
Tax-exempt nonprofit corporations file Form 990, or Form 990-EZ for smaller organizations. A company filing 990 has been recognized as tax-exempt by the IRS, which issues a determination letter confirming that status when it approves the original application.5Internal Revenue Service. Exempt Organizations Rulings and Determinations Letters That letter is a critical record and is regularly requested by donors, grantmakers, and banks.
What If Your Company Is an LLC?
An LLC can file Form 1120 or Form 1120-S even though it isn’t a corporation under state law. If the LLC filed Form 8832, it elected to be taxed as a corporation for federal purposes.6Internal Revenue Service. About Form 8832, Entity Classification Election From there, it could also file Form 2553 for S-corporation treatment. So if the state record says “LLC” but the tax returns are 1120 or 1120-S, you have a limited liability company that elected corporate taxation. The two labels are both correct, describing different things.
IRS Letters That Confirm an Election
Beyond the return itself, the company’s IRS correspondence file will usually settle any doubt. When the business first received its Employer Identification Number after submitting Form SS-4, the IRS sent a confirmation assigning the number, sometimes referencing the entity type.7Internal Revenue Service. Instructions for Form SS-4 More telling are the later notices. IRS Notice CP261 is the letter the IRS sends when it accepts a Form 2553 election, and it states the effective date of S-corporation treatment.8Internal Revenue Service. Understanding Your CP261 Notice A determination letter confirms exempt status for a nonprofit. If none of these special notices exist anywhere in the records, the company is almost certainly a standard C-corporation. If you can’t find the CP261 and think you should have one, call the IRS Business and Specialty Tax Line to verify the entity’s filing status directly.
Is the Corporation Publicly Traded
Public corporations file with the Securities and Exchange Commission; private ones don’t. The fastest check is the SEC’s EDGAR database at sec.gov/edgar/search. Enter the company name, ticker symbol, or CIK number. If filings appear — especially the annual Form 10-K, quarterly Form 10-Q, or current-event Form 8-K — the company is a public reporting corporation.9U.S. Securities and Exchange Commission. EDGAR Full Text Search The cover page of a 10-K lists each class of securities registered under the Securities Exchange Act, the trading symbol, and the exchange the shares trade on, and it also identifies the filer as a large accelerated filer, accelerated filer, non-accelerated filer, smaller reporting company, or emerging growth company.10U.S. Securities and Exchange Commission. Form 10-K No EDGAR results means a private corporation.
Why the Answer Matters
Identifying the type isn’t paperwork housekeeping. Operating under the wrong classification creates real problems that grow the longer they sit.
The costliest mistake involves S-corporation status. If the owners believe the company is an S-corporation but Form 2553 was never properly filed and accepted, the IRS treats it as a C-corporation. The company then owes corporate income tax on every dollar of profit going back to the year the election was supposed to take effect, and the shareholders’ personal returns are wrong because they reported pass-through income the IRS doesn’t recognize.11Internal Revenue Service. S Corporations
Nonprofit corporations face a different risk. A tax-exempt organization that fails to file Form 990 for three consecutive years automatically loses its exempt status. The revocation is effective on the third missed return’s due date, and the IRS cannot reverse it — there is no appeal.12Internal Revenue Service. Automatic Revocation of Exemption Once revoked, the organization pays corporate income tax and can no longer receive tax-deductible contributions. Reinstatement requires a new application, a new user fee, and potentially a fresh round of state exemption filings.
There is also a liability angle. Ignoring the formalities that go with your entity type can weaken the liability protection incorporation was supposed to create. Courts can set aside the corporate structure and hold shareholders personally responsible for company debts when the business fails to observe the formalities its type requires. Running a standard corporation without board meetings, or running a close corporation without the shareholder agreements that make direct management work, both invite that outcome. Knowing exactly what type of corporation you have is the first step to following the right set of rules.