How does a corporation get an EIN?
A corporation files Form SS-4 through 1 of 4 routes: the IRS online tool in 15 minutes, fax in 4 business days to 855-641-6935, mail in 4 weeks, or phone for international applicants at 267-941-1099. Every route costs $0.
| Route | Time to the number | Open without an SSN | IRS fee |
|---|---|---|---|
| Online, irs.gov EIN Assistant | 15 minutes, same session | No, an SSN or ITIN is required | $0 |
| Fax, 855-641-6935 (US-state entities) | 4 business days | Yes | $0 |
| Fax, 855-215-1627 (international) | 4 business days | Yes | $0 |
| Mail, Form SS-4 to the IRS | 4 weeks | Yes | $0 |
| Phone, 267-941-1099 | 1 call | Yes, international applicants only | $0 |
Source: IRS Instructions for Form SS-4, verified July 2026.
The online tool runs Monday to Friday, 7 a.m. to 10 p.m. Eastern, and it closes the session the moment a validation fails. A responsible party with an SSN receives the 9-digit EIN in the same 15-minute session. A corporation whose principal officer holds no SSN files by fax instead, and a return fax number brings the number back in 4 business days. The full route-by-route procedure sits on the how to apply for an ein page.
Have an SSN? irs.gov is free, the online application takes 15 minutes, and the tool issues the EIN in the same session. No SSN? The fax route works at $0, or we file it from $69.
What does a corporation put on Form SS-4?
A corporation checks the Corporation box on line 9a and writes 1120 beside it. Line 1 takes the legal name character for character, line 7a names a principal officer, and line 7b takes that officer’s SSN, ITIN, or the entry Foreign.
Form SS-4 runs 18 numbered lines, and a corporation completes 10 of them. The 3 that decide everything are line 7a, line 7b, and line 9a: the officer, the officer’s number, and the entity type. A wrong entry on any of those 3 is the reason most corporate applications come back.
| Line | What the IRS asks | What a corporation enters |
|---|---|---|
| Line 1 | Legal name of the entity | The corporate name character for character from the articles of incorporation, suffix included. |
| Line 2 | Trade name or DBA | Left blank when the corporation trades under its legal name. A DBA carries no EIN of its own. |
| Line 4a and 4b | Mailing address | A non-US address is accepted. The IRS mails the CP-575 to this address. |
| Line 7a | Name of the responsible party | A principal officer, a natural person. A corporate name is rejected on line 7a. |
| Line 7b | SSN, ITIN or EIN of that officer | The entry Foreign when the principal officer holds no SSN and no ITIN. |
| Line 9a | Type of entity | The Corporation box, with the form number 1120 entered beside it. |
| Line 10 | Reason for applying | Started a new business, hired employees, or banking. The reason does not change the number issued. |
| Line 11 | Date business started or acquired | The incorporation date on the state filing, not the date the application is signed. |
| Line 16 | Principal activity | One activity box plus a plain description of the goods or services sold. |
| Line 18 | Has the applicant ever received an EIN | Yes plus the prior number when the corporation held one before, which blocks a duplicate. |
Source: IRS Instructions for Form SS-4. Verified July 2026.
Fill each line against your incorporation document, then check it once more before filing. A guided walk-through of all 18 lines sits on the form ss-4 page, and the interactive ss-4 form helper builds line 9a and line 7b for you.
How does a corporation file Form 1120?
A C corporation files Form 1120 once a year, with the 9-digit EIN printed in the identification block on page 1. A calendar-year corporation files by the 15th day of the 4th month, April 15, and pays the 21% rate on taxable income.
Form 1120 is the corporate income tax return, and the EIN is what ties it to the entity. The return reports gross income, subtracts deductions, and applies the 21% rate under Internal Revenue Code section 11 to the taxable income that remains. A corporation with a fiscal year files by the 15th day of the 4th month after its year ends, and a 6-month extension to Form 7004 pushes a calendar-year deadline to October 15.
Payroll, excise, and information returns run alongside the 1120 on the same EIN. A corporation with employees files Form 941 each quarter and Form 940 each year, and a corporation that pays a contractor issues a 1099 form. Every one of those forms carries the same 9-digit number the IRS assigned on the CP-575.
Sources: IRS, About Form 1120 and IRS Publication 542, Corporations. Verified July 2026.
How does the 21% corporate rate work?
A C corporation pays a 21% flat rate on taxable income under Internal Revenue Code section 11. It is one bracket, not a schedule, so a corporation with $50,000 of taxable income and one with $5,000,000 apply the same 21% on Form 1120.
The 21% figure replaced the old graduated schedule and applies to the whole of taxable income, with no lower tier and no upper tier. That is the number a corporation multiplies its taxable income by on Form 1120, and it is why the corporate return is arithmetically simpler than a personal one: 1 rate, applied once, on 1 line. The EIN identifies the filer on every year’s 1120.
The rate says nothing about the shareholder. The 21% lands at the entity level, and a second tax lands on the owner only when profit leaves the corporation as a dividend. That 2-layer structure is the subject of the next section, and it is the single fact that pushes many owners toward an S election on Form 2553.
Source: Internal Revenue Code section 11, which sets the 21% corporate rate, and IRS Publication 542. Verified July 2026.
What is corporate double taxation?
Profit is taxed twice. A C corporation pays the 21% rate on Form 1120, then a shareholder pays income tax again on any dividend, reported on the shareholder’s Form 1040. The 2 layers are the defining feature of a C corporation.
Layer 1 falls on the corporation. It earns income, files Form 1120, and pays the 21% rate on what remains after deductions. Layer 2 falls on the owner. When the corporation distributes after-tax profit as a dividend, the shareholder reports it on Form 1040 and pays a second income tax on the same dollars. The EIN sits on layer 1, the SSN on layer 2, and the 2 numbers never merge.
An S corporation election on Form 2553 removes layer 1. The entity keeps the same EIN, files Form 1120-S instead of Form 1120, and passes income straight to shareholders, so the profit is taxed 1 time rather than 2. The trade-offs between the 2 elections are laid out on the ein for s-corp page.
Should you be a C corporation or an S corporation?
A C corporation files Form 1120 and pays the 21% rate, with profit taxed a second time as a dividend. An S corporation files Form 1120-S and passes income through, capped at 100 shareholders and 1 class of stock under Internal Revenue Code section 1361.
| Feature | C corporation | S corporation |
|---|---|---|
| Annual return | Form 1120 | Form 1120-S |
| Entity-level tax | 21% flat rate | None, income passes through |
| Layers of tax | 2, corporate then dividend | 1, at the shareholder |
| Election form | None, the default | Form 2553 |
| Shareholder cap | No limit | 100 shareholders |
| Classes of stock | More than 1 allowed | 1 class only |
| Non-resident owners | Allowed | Barred by IRC 1361 |
| Same EIN after election | n/a | Yes, the number carries over |
Source: Internal Revenue Code section 1361, which caps an S corporation at 100 shareholders and 1 class of stock and bars a non-resident alien shareholder. Verified July 2026.
The EIN is identical either way. A corporation applies once on Form SS-4, receives 1 permanent number, and keeps it whether it stays a C corporation or elects S status on Form 2553 within 2 months and 15 days of the tax year. Filing structures for related entities sit on the ein for llc and ein for partnership pages.
Who is the responsible party for a corporation?
The responsible party is a principal officer, a natural person who controls the corporation, such as the president or the chief executive. Line 7a takes that person’s name and line 7b takes their SSN, ITIN, or the entry Foreign.
The IRS requires 1 responsible party per EIN, and it must be a human being with control over the entity. A board of directors, a parent corporation, and a law firm are all barred from line 7a, because the field rejects any entity name. The number on line 7b is the officer’s own, never the corporation’s, and it exists only to identify the person who signs for the entity.
A principal officer without an SSN or ITIN enters Foreign on line 7b, and the application moves to the fax route at 855-641-6935. No identity document is filed with Form SS-4, and no passport upload is asked for. The EIN that results belongs to the corporation, not to the officer, which is the whole point of the separation set out on the federal tax id number page.
Is the EIN the corporation’s permanent ID?
Yes. The 9-digit EIN is the corporation’s permanent federal ID, distinct from any owner’s SSN. It survives a name change, an address change, and an S election on Form 2553, and it is printed once on the CP-575.
A corporation is a separate taxpayer, so its EIN outlives the people who run it. The number stays fixed while officers change, while the registered address moves, and while the entity elects or revokes S status. An address change is filed on Form 8822-B within 60 days, and the 9-digit number does not change. The only event that forces a new EIN is a new corporate charter from a state, or a conversion to a different entity type.
The CP-575 is the 1 letter the IRS issues when it assigns the number, and a bank verifies the corporation against it before opening an account. Its anatomy is broken down on the cp 575 page, and the broader business context sits on the ein for business page.
Source: IRS, Do You Need a New EIN. Verified July 2026.
What does an EIN for a corporation cost?
The IRS charges $0 for a corporate EIN on all 4 routes, and the number never renews, so year 2 costs $0. ein-number.com charges $69 or $99, and other filing services run from $59.99 to $200, verified 2026.
| Filed by | Price | Accuracy guarantee | Year 2+ |
|---|---|---|---|
| Yourself, direct to the IRS | $0 | Not stated | $0 |
| ein-number.com, Standard | $69 | Accuracy guaranteed · filed by fax in 8 business days | $0 |
| ein-number.com, Fast | $99 | Accuracy guaranteed · filed within 24 hours, 7 business days total | $0 |
| Northwest | $200 | Not stated | $0 |
| Rocket Lawyer | $59.99 | Not stated | $0 |
Competitor prices verified July 2026. The IRS fee is $0 on every route, in all 50 states.
The EIN itself carries no price on any row. What differs is who absorbs the risk of a rejection. The $69 Standard tier covers Form SS-4 double-checked against your articles of incorporation by a senior reviewer, fax filing within 8 business days, and 4 tracked stages. The $99 Fast tier files within 24 hours with the IRS call included, 7 business days total. Both refund in full if we make an error. A corporation with an SSN and 15 minutes pays $0 at irs.gov instead, and we say so on every page.
A cost-by-route breakdown for every entity type sits on the ein cost page, and the new-EIN rules for a corporation are on the do i need an ein page. To file for your corporation now, get started.