The IRS issues Employer Identification Numbers at no charge, and the online application at IRS.gov EIN application delivers your nine-digit number instantly — but only if you understand exactly which entity type to select and which tax obligations attach the moment that number is assigned. In 2026, those obligations include a $176,100 Social Security wage base, a $24,500 employee 401(k) deferral ceiling, and a $206.50 Medicare Part B premium environment that makes payroll accuracy more consequential than ever for employees approaching retirement.
What an EIN Is, Who Assigns It, and the Nine-Digit Structure
An EIN — formally called an Employer Identification Number, also known as a Federal Employer Identification Number (FEIN) or Federal Tax Identification Number — is a unique nine-digit number in the format XX-XXXXXXX assigned by the IRS to identify a business entity for federal tax purposes. The first two digits are a prefix that historically indicated the IRS campus that processed the application; today they reflect the online or phone channel used.
The IRS assigns EINs to sole proprietors with employees, partnerships, corporations, S corporations, LLCs electing corporate taxation, estates, trusts, nonprofits, churches, and certain individuals who are not employers but need a tax ID for specific filings. A sole proprietor with no employees and no excise tax obligations generally does not need an EIN — a Social Security Number suffices — but many sole proprietors obtain one anyway to avoid sharing their SSN with clients or vendors.
The Four Ways to Apply for an EIN in 2026
The IRS offers four application methods: online, fax, mail, and telephone (for international applicants only). Online is the only method that produces an immediate EIN confirmation you can use the same day.
Online (Form SS-4 via IRS.gov): Available Monday through Friday, 7 a.m. to 10 p.m. Eastern. The session must be completed in one sitting — there is no save-and-return function. The responsible party must have a valid SSN, ITIN, or existing EIN. At the end of the session, the IRS displays your EIN and allows you to download a confirmation notice (CP 575).
Fax (Form SS-4): Processing takes approximately four business days. The IRS fax number varies by state; the current list is published at IRS.gov EIN application methods.
Mail (Form SS-4): Processing takes four to five weeks. Use this only when fax or online is unavailable.
Telephone (international applicants): Call 267-941-1099 (not toll-free), Monday through Friday, 6 a.m. to 11 p.m. Eastern.
Form SS-4: Every Line That Matters in 2026
Form SS-4 is the official application for an EIN. Even if you apply online, the IRS online wizard maps directly to SS-4 line items, so understanding the form prevents errors that delay or void your application.
Line 1 — Legal name: Use the exact legal name of the entity as it appears in your formation documents — articles of incorporation, partnership agreement, or trust instrument. For a sole proprietor, use your personal legal name.
Line 7a/7b — Responsible party: This is the individual who controls, manages, or directs the entity and its assets. For a corporation, this is typically a principal officer. For a partnership, a general partner. The IRS requires the responsible party’s SSN or ITIN — not another EIN — for most entity types. This rule, tightened in 2014, prevents shell-company abuse.
Line 9a — Entity type: Selecting the wrong entity type is the most common SS-4 error. A single-member LLC that has not elected corporate taxation is a disregarded entity; its owner files Schedule C (or Schedule E for rental) and may or may not need an EIN depending on whether it has employees or excise tax obligations. An LLC that has elected S-corp status must select “S Corporation” — not “LLC” — to ensure correct filing requirements are assigned.
Line 10 — Reason for applying: Options include “Started new business,” “Hired employees,” “Banking purpose,” “Changed type of organization,” “Purchased going business,” “Created a trust,” and others. Choose the reason that most accurately reflects why you need the EIN; this affects which returns the IRS expects you to file.
| Entity Type | Needs EIN? | Primary Return Filed |
|---|---|---|
| Sole proprietor, no employees | Usually no (SSN suffices) | Schedule C on Form 1040 |
| Sole proprietor with employees | Yes | Form 941 (payroll); Schedule C |
| Single-member LLC (disregarded) | Yes, if employees or excise | Schedule C on Form 1040 |
| Partnership | Yes | Form 1065 |
| C Corporation | Yes | Form 1120 |
| S Corporation | Yes | Form 1120-S |
| Estate | Yes | Form 1041 |
| Trust (non-grantor) | Yes | Form 1041 |
| Nonprofit / 501(c)(3) | Yes | Form 990 series |
EIN and Payroll: The $176,100 Wage Base Every Employer Must Track in 2026
The moment you hire an employee, your EIN becomes the anchor for every payroll tax deposit, Form 941 filing, W-2 issuance, and unemployment tax return. In 2026, the Social Security wage base is $176,100, meaning you withhold 6.2% Social Security tax from each employee’s wages up to that threshold and match it with an equal 6.2% employer contribution. Medicare’s 1.45% (employee) plus 1.45% (employer) applies to all wages with no cap.
Employees earning above $200,000 trigger the Additional Medicare Tax of 0.9%, which the employer must withhold but does not match. The employer’s obligation is purely to withhold once wages cross $200,000 for that employee in that calendar year; the employee reconciles on Form 1040 if their combined household income exceeds the applicable threshold ($250,000 married filing jointly, $200,000 single).
Payroll tax deposits are due on a schedule the IRS assigns based on your lookback period — the total taxes reported on Form 941 during a 12-month lookback window ending June 30. If you reported $50,000 or less, you are a monthly depositor. Above $50,000, you are a semi-weekly depositor. New employers are automatically monthly depositors for their first calendar year. See IRS Publication 15 for the complete deposit schedule rules.
The $24,500 401(k) Limit and Who Gets the $11,250 Super Catch-Up in 2026
If your business sponsors a 401(k), SIMPLE IRA, or other qualified retirement plan, the EIN on your plan documents must match the EIN on your payroll records and Form 5500. Mismatches trigger IRS correction procedures that are time-consuming and sometimes costly.
For 2026, the employee deferral limit for 401(k), 403(b), and most 457(b) plans is $24,500. Employees age 50 and older can contribute an additional $8,000 catch-up, for a total of $32,500. Employees ages 60 through 63 qualify for the SECURE 2.0 “super catch-up” of $11,250 instead of the standard $8,000, bringing their maximum to $35,750. Employers must update plan administration systems to apply the correct catch-up limit by age bracket — the IRS has not extended any relief for plans that apply the wrong limit.
IRA contributions are separate from 401(k) limits. The 2026 IRA contribution limit is $7,500, with a $1,100 catch-up for those 50 and older, bringing the total to $8,600. These limits apply per person, not per account. An employer’s EIN does not appear on IRA records — IRAs are individual accounts — but business owners who use a SEP-IRA must use their business EIN on the SEP plan documents.
EIN for Estates and Trusts: The April 15, 2026 Filing Deadline Connection
When a person dies, their estate becomes a separate taxpayer and requires its own EIN. The executor or administrator applies for the estate EIN on Form SS-4, selecting “Estate” as the entity type and entering the decedent’s name and SSN. The estate EIN is then used on Form 1041 (U.S. Income Tax Return for Estates and Trusts) and on any estate tax return (Form 706) if the gross estate exceeds the 2026 exclusion of $13.99 million.
For estates of decedents who died in 2025, the Form 706 is due nine months after the date of death, with a six-month extension available. Form 1041 for the estate’s fiscal year follows the same April 15, 2026 deadline that applies to individual returns for the 2025 tax year — or the 15th day of the fourth month after the estate’s fiscal year ends if the estate uses a fiscal year other than the calendar year.
EIN Verification, Replacement CP 575, and the 147C Letter in 2026
The IRS does not maintain a public EIN lookup database. To verify your own EIN, locate the original CP 575 confirmation notice mailed after your application. If you cannot find it, call the IRS Business and Specialty Tax Line at 800-829-4933 (Monday through Friday, 8 a.m. to 8 p.m. local time) and request a 147C letter — the IRS’s official EIN verification letter. The 147C can be faxed to you immediately or mailed.
You launched a sole proprietorship in March 2026, hired your first employee in April 2026, and a client asks for your W-9. You have been using your SSN for all business purposes. You need to decide whether to obtain an EIN now, continue using your SSN, or use a third-party EIN service.
Banks, state agencies, and payroll processors routinely require EIN verification before opening business accounts or processing payroll. The 147C letter is accepted everywhere the CP 575 is accepted. The IRS does not reissue CP 575 notices; the 147C is the permanent replacement.
EIN Scams and Third-Party Filers: What the IRS Charges vs. What You Should Pay
Dozens of websites charge $50 to $300 to “obtain” an EIN for you. They submit Form SS-4 on your behalf — a service that takes about ten minutes online and costs nothing directly from the IRS. These services are legal but unnecessary for most applicants. If you use a third-party designee (Line 18 on Form SS-4), that designee can receive the EIN on your behalf, but you remain the responsible party and retain all tax obligations.
The IRS has flagged fraudulent EIN mills that list themselves as the responsible party on SS-4 applications, effectively hijacking the business’s tax identity. If you discover that someone else is listed as the responsible party on your EIN, contact the IRS immediately at 800-829-4933 to correct the record. The IRS does not charge to update responsible party information — use Form 8822-B (Change of Address or Responsible Party — Business).
| Key Limit / Figure | 2025 | 2026 |
|---|---|---|
| Social Security wage base | $176,100 | $176,100 |
| 401(k) employee deferral | $23,500 | $24,500 |
| 401(k) catch-up (50+) | $7,500 | $8,000 |
| 401(k) super catch-up (60–63) | $11,250 | $11,250 |
| IRA contribution limit | $7,000 | $7,500 |
| Standard deduction (single) | $15,000 | $15,750 |
| Standard deduction (married joint) | $30,000 | $31,500 |
| Estate tax exclusion | $13.61M | $13.99M |
| Annual gift tax exclusion | $18,000 | $19,000 |
Self-Employed Business Owners: EIN, Schedule C, and the $15,750 Standard Deduction for 2026
A self-employed individual operating as a sole proprietor with no employees can file Schedule C using their SSN. But obtaining an EIN is still advisable for three practical reasons: it protects your SSN from exposure on 1099 forms issued to contractors, it is required if you open a business bank account at most institutions, and it is required if you later hire even one employee.
Confirm you have a valid Taxpayer Identification Number (SSN, ITIN, or existing EIN) to serve as the responsible party’s TIN on Form SS-4, as the IRS will reject applications without one *
Verify your business entity is legally formed (e.g., LLC articles filed, corporation charter approved) in your state before applying, since the IRS issues EINs to existing legal entities *
Apply directly through IRS.gov at no cost—the EIN is free, and any third-party service charging a fee (often $50–$300) is optional and not affiliated with the IRS
Ensure only one EIN application is submitted per responsible party per day, as the IRS enforces a strict one-EIN-per-day limit and will reject duplicates *
Choose the correct reason for applying on Form SS-4 (e.g., started new business, hired employees, opened a bank account) to avoid processing delays or IRS follow-up
If applying by fax or mail instead of online, allow 4 business days (fax) or 4–5 weeks (mail) for processing—plan ahead if you need the EIN for a tax deadline or bank account opening
For the 2025 tax year filed by April 15, 2026, the standard deduction for a single filer is $15,750. A sole proprietor who itemizes instead of taking the standard deduction can deduct business expenses directly on Schedule C — those deductions are separate from and in addition to the standard deduction or itemized deductions on Schedule A. The IRS standard mileage rate for business use of a vehicle in 2026 is 70 cents per mile, applicable to miles driven in the 2026 tax year (reported on the 2026 return filed in 2027).
Self-employed individuals also pay both the employee and employer halves of FICA — 12.4% Social Security (on net self-employment income up to $176,100) plus 2.9% Medicare, for a combined 15.3% self-employment tax. Half of that SE tax is deductible as an above-the-line adjustment on Form 1040. These calculations all flow through the Schedule SE, which is filed under the taxpayer’s SSN — not the business EIN — unless the business is a partnership or corporation.
SSA announces the 2027 COLA in October 2026, and the IRS will release 2027 inflation-adjusted limits — including any changes to the 401(k) deferral ceiling and standard deduction — in a new Revenue Procedure expected by November 2026.
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