Key takeaways. It depends on the LLC. A single-member LLC can typically keep using your sole proprietor EIN if it has no employees, owes no excise tax and isn’t taxed as a corporation. A multi-member LLC needs a new EIN. Sole proprietors without employees often don’t need an EIN at all.
The IRS ties a new EIN to changes in ownership or structure. Forming a single-member LLC changes your legal structure, but for federal tax the LLC is usually treated the same way as your sole proprietorship.
Can I use my sole proprietor EIN for my LLC?
Yes, for a single-member LLC that has no employees, owes no excise tax and hasn’t elected to be taxed as a corporation or S corporation. If any of those change, the LLC needs its own EIN.
That rule comes from the IRS page “When to get a new EIN”. The IRS single-member LLC page adds that an LLC with employees must use its own name and EIN for employment taxes.
When does a sole proprietor need a new EIN?
If you already have an EIN as a sole proprietor, you need a new one when you incorporate, form a partnership or declare bankruptcy. A name change, a move or owning several businesses doesn’t require one.
| Change | New EIN needed? |
|---|---|
| You change your business name or location | No |
| You own more than one business | No |
| You form a single-member LLC with no employees, no excise tax and no corporate tax election | No. You can use the sole proprietor EIN. |
| Your single-member LLC hires employees or owes excise tax | Yes |
| You take on partners or form a multi-member LLC | Yes |
| You incorporate | Yes |
| You declare bankruptcy | Yes |
Source: IRS: When to get a new EIN (reviewed Jul 21, 2026) and IRS: Single member LLCs.
Does a sole proprietorship need an EIN at all?
Usually not. A sole proprietor without employees, excise tax returns or a Keogh plan can use a Social Security number and report business income on Schedule C (Form 1040).
The IRS “Do you need an EIN?” checklist says you need one if any of these apply.
- You hire employees
- You file employment, excise, or alcohol, tobacco and firearms tax returns
- You withhold tax on income, other than wages, paid to a non-resident alien
- You have a Keogh plan
- You work with trusts, estates, nonprofits, farmers’ cooperatives or plan administrators
What changes for a multi-member LLC?
A multi-member LLC is taxed as a partnership by default, so the IRS requires it to have its own EIN. It can’t use the EIN from your sole proprietorship.
The LLC files a partnership return and gives each member a Schedule K-1, as described on the IRS LLC page. See LLC taxes for how that works.
Should you get an EIN as a sole proprietor anyway?
Many sole proprietors do, mainly to keep their Social Security number off client paperwork. It also makes hiring and opening a bank account simpler later.
- Clients who issue you a 1099 ask for an SSN or EIN. Giving the EIN keeps your SSN private.
- Some banks ask for an EIN before opening a business bank account.
- With an EIN in place, you can set up payroll and file employment taxes as soon as you hire.
The IRS doesn’t charge for an EIN. How to get an EIN walks through the application.
FAQ
Generally one. The IRS says a sole proprietor doesn’t need a new EIN to own more than one business. A new number comes with a structural change, such as incorporating or forming a partnership.
Either works if none of the IRS conditions apply to you. Many owners choose an EIN to protect their SSN and to be ready to hire.
Not to get a new EIN, if the LLC qualifies to use your sole proprietor number. If the responsible party changes, the IRS says to report it on Form 8822-B within 60 days.
Check the IRS notice from when you applied, your past tax returns or your business bank. You can also call the IRS Business and Specialty Tax Line at 800-829-4933 (IRS). See how to find a lost EIN.
Ready to make the switch? Start with forming your LLC, then check this table again before you apply for anything new.
Sources
- IRS: Get an employer identification number (reviewed Oct 16, 2026)
- IRS: Employer identification number (reviewed Jul 17, 2026)
- IRS: When to get a new EIN (reviewed Jul 21, 2026)
- IRS: Single member limited liability companies (reviewed Jul 27, 2026)
- IRS: Do you need an EIN?
- IRS: Responsible parties and nominees (reviewed Nov 8, 2026)