Do I Need an EIN, or Can I Just Use My Social Security Number?
A plain-words guide for a sole proprietor — one person running a business, with no employees yet.
This page is general information, not tax or legal advice.
The short answer
If you are a sole proprietor, you have no employees, and none of the triggers listed below apply to you, you can use your Social Security number (SSN) as your taxpayer ID.
You do not have to get an EIN just because you started a one-person business.
First, what is an EIN?
EIN stands for Employer Identification Number.
It is an ID number for a business, issued by the IRS.
An EIN does not change how a sole proprietor's taxes are figured. It is just an ID number.
When you must get an EIN
You must get an EIN if any of these are true:
- You hire employees, or you plan to hire employees.
- You file employment tax returns or excise tax returns.
- You have a qualified retirement plan, also called a Keogh plan.
- You elect to have the business taxed as a corporation or an S corporation.
- You file for bankruptcy for the business.
If none of those apply, your SSN works as your taxpayer ID.
A simple example
Maria sells handmade soap at a farmers market. She works alone. She has no employees.
Her SSN works for her business taxes.
The day she hires a helper, she needs an EIN.
An EIN is free
An EIN is free from the IRS.
Apply on IRS.gov.
Watch out: Never pay a lookalike website that charges for an EIN. The real IRS does not charge for one. Go to IRS.gov yourself.
Why some people get one anyway
These are common practice, not legal requirements:
- Many banks ask for an EIN to open a business bank account.
- Using an EIN on Form W-9 forms you hand to clients means handing out your SSN less often.
For many one-person businesses, that privacy reason alone is worth it — even when the IRS does not require an EIN.
So, which should you use?
- No employees and no triggers above? Your SSN is allowed.
- Hiring, or any trigger above applies? Get an EIN.
- Want to hand out your SSN less, or your bank asks for one? Getting a free EIN from IRS.gov is a common choice.
Sources and freshness
Checked November 2026
Sources: IRS page “Do you need an EIN?” and IRS Publication 1635.
This page is general information, not tax or legal advice. If your situation is not simple, talk to a qualified tax professional.