How to Register an S Corp: Form 2553, Deadlines, and CP261

To register an S corp, you first form a corporation or LLC with your state, obtain an Employer Identification Number from the IRS, and then file IRS Form 2553 to elect S corporation tax treatment. The election itself is free; you pay only the state fees for forming the underlying entity. Timing matters: Form 2553 generally has to reach the IRS by the 15th day of the third month of the tax year you want the election to cover.

An S Corp Is a Tax Election, Not a State Filing

There is no “S corporation” formation document at the state level. An S corp is a federal tax classification the IRS applies to an already-existing business entity. When the election is approved, your company keeps its legal structure (corporation or LLC) but its profits and losses pass through to shareholders’ personal returns instead of being taxed at the entity level and again as dividends.1Internal Revenue Service. S Corporations

That distinction shapes the whole process. You are not registering a new kind of company. You are creating an ordinary state-law entity and then asking the IRS to tax it differently.

Step 1: Form Your State Entity

Before the IRS will look at an S corp election, you need a legal entity for it to apply to. That means filing articles of incorporation to create a corporation, or articles of organization to create an LLC, with your state’s business filing office. Those documents establish the entity, provide liability protection, and set the governance rules.

State formation fees typically run from roughly $35 to $500 or more. Most states also charge annual or biennial report fees, ranging from $0 to several hundred dollars, to keep the entity in good standing. Without an active, properly registered entity, the IRS has nothing to apply the S election to.

Step 2: Confirm You Meet the Federal Eligibility Rules

The Internal Revenue Code sets structural requirements the company must meet when it elects S status and every day afterward.2Office of the Law Revision Counsel. 26 USC 1361 – S Corporation Defined

  • The business must be a domestic entity, organized under U.S. federal or state law.
  • It can have no more than 100 shareholders. Members of the same family, up to six generations, count as a single shareholder for this limit.
  • Shareholders must be individuals who are U.S. citizens or resident aliens. Corporations, partnerships, and nonresident aliens cannot hold shares. Grantor trusts, Qualified Subchapter S Trusts, Electing Small Business Trusts, and certain estates are permitted.
  • The company can have only one class of stock. Different voting rights are fine, but every share must carry identical rights to distributions and liquidation proceeds.
  • Certain entities are ineligible outright, including banks using the reserve method for bad debts, insurance companies taxed under a special subchapter, and domestic international sales corporations.

Breaking any of these rules after the election is in effect can involuntarily terminate S status and revert the company to C corporation taxation.

Step 3: Get an Employer Identification Number

Every S corp needs an EIN before Form 2553 goes in. You can apply for one online through the IRS website at no cost, and the number is issued immediately once the application is approved.3Internal Revenue Service. Get an Employer Identification Number The online application must be completed in one sitting; it cannot be saved and returned to. If you would rather apply by paper or fax, use Form SS-4.4Internal Revenue Service. About Form SS-4, Application for Employer Identification Number (EIN)

Step 4: Complete Form 2553

Form 2553, “Election by a Small Business Corporation,” is the document that actually makes the S election.5Internal Revenue Service. About Form 2553, Election by a Small Business Corporation Download it from IRS.gov. Every field has to be accurate; sloppy entries are a common reason elections come back rejected.

Company Information

The form asks for the corporation’s legal name, EIN, date of incorporation, state of incorporation, and mailing address. You will also enter the effective date of the election (the first day of the tax year you want S treatment to start) and select a tax year-end, which for most small businesses is December 31. Include a daytime contact number so the IRS can resolve small issues without holding up the approval.

Shareholder Information and Consent

For each shareholder, the form requires a full legal name, mailing address, Social Security number (or EIN for trusts and estates), the number of shares or percentage of ownership held, and the date the stock was acquired.6Internal Revenue Service. Form 2553, Election by a Small Business Corporation

Every shareholder must sign and date the consent statement. The election requires unanimous agreement, and the IRS will not treat the form as timely filed if a signature is missing. Where a shareholder and spouse have a community property interest in the stock or its income, both must consent.7Internal Revenue Service. Instructions for Form 2553 A corporate officer authorized to sign the company’s tax return also has to sign.

Step 5: File by the Deadline

When you file determines when the election takes effect. Two windows put the election in place for the current tax year:8Office of the Law Revision Counsel. 26 USC 1362 – Election; Revocation; Termination

  • Any time during the tax year before the one you want the election to cover.
  • On or before the 15th day of the third month of the current tax year. For a calendar-year company, that means March 15. For a new company with a first tax year of two and a half months or less, the deadline is two months and 15 days after the tax year begins.

Miss both windows and the election will not apply until the next tax year, leaving the company taxed as a C corp for the current one unless it qualifies for late relief.

Where to Send It

As of 2026, Form 2553 is accepted only by mail or fax; there is no e-filing option. The correct address and fax number depend on where the business is located:9Internal Revenue Service. Where to File Your Taxes (for Form 2553)

  • Eastern states (Connecticut through Wisconsin, plus the District of Columbia): mail to Department of the Treasury, Internal Revenue Service, Kansas City, MO 64999; fax 855-887-7734.
  • Western and southern states (Alabama through Wyoming, plus Alaska, Hawaii, and U.S. territories): mail to Department of the Treasury, Internal Revenue Service, Ogden, UT 84201; fax 855-214-7520.

Faxing is faster and gives you immediate proof of transmission. If you mail the form, use certified mail or another delivery-confirmation method so you can document the filing date. The IRS generally takes about 60 days to process the election.10Internal Revenue Service. Instructions for Form 2553

If You Missed the Deadline

Revenue Procedure 2013-30 offers a simplified way to have a late election treated as timely if the company meets four conditions:11Internal Revenue Service. Revenue Procedure 2013-30

  • The company intended to be classified as an S corp starting on the requested effective date.
  • The only reason the election failed is that Form 2553 was not filed on time.
  • There is reasonable cause for the late filing, and the company acted promptly to fix it once discovered.
  • The corporation and every shareholder reported income on all returns consistently with S corp treatment.

To request relief, file a completed Form 2553 with “FILED PURSUANT TO REV. PROC. 2013-30” written across the top and attach a signed statement explaining the delay and the corrective steps taken. Every shareholder who held stock from the intended effective date through the filing date must sign and confirm consistent reporting.

The request generally must be filed within three years and 75 days of the intended effective date. If the corporation has been filing returns as an S corp all along and the IRS has not raised an issue within six months of the first return, the three-year limit does not apply.11Internal Revenue Service. Revenue Procedure 2013-30

Confirmation: The CP261 Notice

When the IRS approves the election, it mails a CP261 notice stating the effective date and confirming S corp treatment.12Internal Revenue Service. CP261 Notice Keep the notice in your permanent corporate records; you may need it for bank financing, audits, or later IRS questions about your status.

If the election is denied, a separate notice explains why. The usual causes are missing shareholder signatures, an ineligible shareholder, or incorrect entity information, and the fix is generally to correct and refile.10Internal Revenue Service. Instructions for Form 2553

Check Whether Your State Needs a Separate Election

A federal S election does not automatically carry over to state income tax. Many states honor the federal election with no extra filing, but some require a separate state-level election form with its own deadlines and consent rules, and some charge a fee for it. Skip a required state filing and the business can end up taxed as a C corp at the state level even while the IRS treats it as an S corp. Check with your state’s department of revenue to confirm the requirement.

What You Have to File Every Year

S corp status stays in place indefinitely once approved and does not need to be renewed, but the company picks up recurring federal filing duties.

Form 1120-S

Every S corp files Form 1120-S annually, even when the entity owes no income tax. For calendar-year corporations the return is due March 15, or the next business day if that falls on a weekend. The 2025 return, for example, is due March 16, 2026.13Internal Revenue Service. 2025 Instructions for Form 1120-S Late filing carries a penalty of $255 per shareholder for each month or partial month the return is overdue, up to 12 months.14Internal Revenue Service. Instructions for Form 1120-S (2025)

Schedule K-1

The corporation issues a Schedule K-1 to every shareholder reporting their share of income, deductions, and credits, and files a copy with the IRS. Shareholders use the K-1 on their personal returns and owe tax on their share of corporate income whether or not it was actually distributed.15Internal Revenue Service. Shareholder’s Instructions for Schedule K-1 (Form 1120-S)

Quarterly Estimated Tax

S corp income passes through without withholding, so shareholders generally have to make quarterly estimated tax payments on Form 1040-ES if they expect to owe $1,000 or more on their personal return.16Internal Revenue Service. Estimated Taxes

What It Costs

Filing Form 2553 itself is free. The real costs sit on either side of the election:

  • State entity formation: roughly $35 to $500 depending on the state.
  • Annual or biennial state reports: $0 to several hundred dollars.
  • State franchise or entity-level taxes: some states impose a minimum annual tax on S corps, from under $100 to $800 or more.
  • Payroll setup: shareholder-employees must be paid a salary, so you will need payroll tax accounts and either an in-house process or a payroll provider.
  • Tax preparation: the S corp files its own Form 1120-S separate from your personal return, which typically raises accounting fees compared with a sole proprietorship or single-member LLC.