A federal tax identification number, commonly called an EIN, is a unique nine-digit code assigned by the Internal Revenue Service to identify business entities and certain other organizations in the United States.
Think of it as a Social Security number for your business, enabling you to hire employees, open business bank accounts, and file taxes accurately and efficiently.
| Term | Format | Primary Use | Issuing Agency |
|---|---|---|---|
| Federal Tax Identification Number | XX-XXXXXXX | Identify business entities for tax and regulatory purposes | Internal Revenue Service (IRS) |
| Employer Identification Number | XX-XXXXXXX | Used on employment tax returns and wage reports | Internal Revenue Service (IRS) |
| EIN Confirmation Letter | CP 575 | Official IRS notice of assigned EIN | Internal Revenue Service (IRS) |
| Responsible Party | Individual name and title | Person with ultimate responsibility for managing the entity | Internal Revenue Service (IRS) |
What Is EIN and When Is It Required
An Employer Identification Number is required whenever a business has employees, operates as a corporation or partnership, or files certain tax returns such as excise or employment taxes.
Even some single-member limited liability companies choose to obtain an EIN to separate personal and business finances, simplify banking, and avoid using their Social Security number on invoices and forms.
Sole proprietors without employees can often use their Social Security number, but using an EIN can reduce identity theft risk and make it easier to switch business structures later.
How to Apply for a Federal Tax Identification Number
Applying for an EIN is generally free and can be completed online, by fax, by mail, or by phone if the applicant is not in the United States.
The online application is immediate, provides instant confirmation, and issues a printable EIN Confirmation Letter that you can use to open accounts or update filings.
Before applying, prepare your legal entity name, address, and the name and title of the responsible party so the application process goes smoothly.
Uses of a Federal Tax Identification Number
Banks require an EIN to open business checking or savings accounts and to set up payment processing for merchants.
Employers must include the EIN on payroll records, W-2 forms, and federal tax deposits to comply with employment tax rules.
Entities that file excise taxes, alcohol and tobacco taxes, or environmental taxes also rely on the EIN to track liabilities and payments accurately.
Common Mistakes and Misunderstandings
Some people believe that an EIN is the same as a business license or a state tax ID, but it is specifically a federal identifier for tax purposes.
Others think that once obtained, the number never changes, yet in rare cases a business can request a new EIN if the ownership structure changes significantly.
Using an EIN incorrectly on personal tax returns or sharing it in insecure settings can lead to identity fraud, so it should be stored and shared carefully.
Key Takeaways for Responsible Business Owners
- An EIN is a free, nine-digit federal identifier assigned by the IRS for tax and business purposes.
- You typically need an EIN if you have employees, operate as a corporation or partnership, or file specific tax returns.
- Applying online provides immediate confirmation and a printable document you can use right away.
- Use your EIN on business documents, tax returns, and bank applications, but never for personal identification.
- Keep your EIN secure and verify requirements with the IRS or a tax professional when your business structure changes.
FAQ
Reader questions
Do I need a federal tax identification number if I am a sole proprietor?
Not always, but many sole proprietors obtain an EIN to keep their Social Security number private, simplify bank processes, and prepare for future business changes.
Can I use my federal tax identification number to open a personal bank account?
No, EINs are intended for business and tax use only, so you should use your Social Security number for personal accounts.
How long does it take to receive confirmation after applying online?
When you apply online, the IRS provides immediate confirmation and you can print the EIN Confirmation Letter right away.
What happens to my federal tax identification number if my business changes ownership?
The existing EIN generally stays the same, but in certain ownership change scenarios the IRS may assign a new number, so it is important to check current rules.