How to Get an EIN Number in Massachusetts Online

You can get an EIN in Massachusetts online for free through the IRS EIN Assistant, and if you finish the session in one sitting the number is issued to you immediately on screen. An EIN is the nine-digit federal tax ID the IRS assigns to businesses, and you’ll need it to open a business bank account, hire employees, file federal and state taxes, and register with the Massachusetts Department of Revenue through MassTaxConnect.¹

The online portal is open Monday through Friday, 6:00 a.m. to 1:00 a.m. Eastern Time the next morning. Two rules matter before you start: the session expires after 15 minutes of inactivity with no way to save your progress, and only one EIN is issued per responsible party per day.²

Do You Actually Need an EIN

Corporations, partnerships, and multi-member LLCs need an EIN whether or not they have employees.² Sole proprietors have more flexibility and can use a Social Security Number for tax purposes when working alone, but must get an EIN if they hire employees, sponsor a Keogh or Solo 401(k), file excise tax returns (alcohol, tobacco, firearms, and similar), or buy or inherit an existing business they’ll run as a sole proprietorship.

Even when it isn’t legally required, many Massachusetts banks ask for an EIN before opening a business account,³ and having one keeps you from handing your personal SSN to vendors and clients. A sole proprietor without employees can register with the Department of Revenue using an SSN alone and add an EIN later if things change.¹

One warning worth carrying with you: the IRS charges nothing for an EIN. Third-party sites that ask for a fee are reselling a free service.²

What to Have Ready Before You Open the Portal

Because the online form can’t be saved, pull everything together before you start:

Your entity type: sole proprietor, single-member LLC, multi-member LLC, corporation, partnership, trust, estate, or nonprofit. This choice determines which federal forms you’ll file going forward.
Your legal name, exactly as it appears on your formation documents filed with the Massachusetts Secretary of the Commonwealth. If you’re a sole proprietor with no state filing, this is your personal legal name.⁴
Any trade name or DBA. If your business operates under a name different from its legal name, you must file a business certificate in Massachusetts and include the DBA on the application.⁵
A Massachusetts mailing address where the IRS can send correspondence.
The responsible party’s information. Every EIN application requires one individual who owns or controls the entity, and that person must supply an SSN or ITIN. The responsible party must be a person, not another business.⁶
Your reason for applying (starting a new business, hiring employees, banking purposes, and so on).

Make sure the name and address you plan to enter match your Massachusetts formation paperwork. Inconsistencies between the two are a common source of delays.

Applying Through the IRS EIN Assistant

The online tool walks you through the same information Form SS-4 asks for on paper, one question at a time.⁷ A typical session runs in this order:

Choose your entity type and, where prompted, a sub-classification (for example, LLC with one member versus more than one).
Confirm why you’re applying — new business, hired employees, banking, a change in organization, and similar reasons.
Enter the responsible party’s legal name and SSN or ITIN.
Enter the business legal name, any trade name, and the Massachusetts mailing address.
Answer the activity questions (start date, expected employees over the next 12 months, principal business activity).
Choose how you want to receive the confirmation letter — you can view and download it at the end of the session or wait for it in the mail.

Once you submit, the portal displays your EIN on screen. Save or print the confirmation before closing the browser; that PDF is your immediate proof of the number while the mailed letter is on its way.

If a Third Party Is Filing for You

If an attorney, accountant, or formation service is applying for you and lists their own address or phone number matching yours, the online tool can’t accept the application, and it has to be submitted by fax or mail instead.⁸ The online route otherwise assumes you’re applying as, or on behalf of, the responsible party directly.

If You’re Outside the United States

The online EIN Assistant is only available to applicants whose principal business, office, or legal residence is in the United States or a U.S. territory. Applicants without a U.S. presence apply by phone at 267-941-1099 (not toll-free), Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern Time.⁸

What You Get Back

Online applicants receive the EIN on screen and can download a confirmation immediately. The IRS also mails a formal notice, CP 575, to your Massachusetts address within about four weeks. It lists your EIN, business name, filing address, and the federal tax forms your business is required to file.⁹

Keep the CP 575 in a safe place. Banks, state agencies, and licensing authorities routinely ask for it to verify your tax status, and having it handy speeds up registering for Massachusetts taxes and any professional licenses you need.

If you lose the CP 575, you have two options: request an entity transcript online, or call the IRS Business and Specialty Tax Line at 800-829-4933 (Monday through Friday, 7:00 a.m. to 7:00 p.m. local time; callers in Alaska and Hawaii use Pacific Time) to request Letter 147C, which confirms your existing EIN.⁹

Registering With MassTaxConnect

Once you have the EIN, most Massachusetts businesses register with the Department of Revenue through MassTaxConnect, the state’s online system for filing and paying state taxes.¹⁰ During registration you’ll select the tax types that apply to your business, which may include:

Sales and use tax, if you sell tangible goods.
Meals, food, and beverage tax, if you sell prepared food or drinks.
Withholding and Paid Family and Medical Leave, if you have employees on payroll.
Room occupancy tax, if you rent out lodging, including short-term rentals.
Corporate excise tax, if you operate as a corporation in Massachusetts.

After the Department of Revenue approves your registration, it mails a registration certificate for each tax type you selected.¹⁰

When You Need a New EIN or Have to Update the Old One

A change of business name or address does not, by itself, require a new EIN.¹¹ You generally need a new one when ownership or legal structure changes. Common triggers by entity type:

Sole proprietors: incorporating, forming a partnership, or filing for bankruptcy.
Corporations: receiving a new charter from the Secretary of the Commonwealth, converting to a partnership or sole proprietorship, or merging to create a new corporation.
Partnerships: incorporating, dissolving and forming a new partnership, or one partner taking over as a sole proprietor.
LLCs: terminating and forming a new corporation or partnership, or a single-member LLC that must file excise or employment taxes.

If your business moves or the responsible party changes, you don’t need a new EIN, but you do have to notify the IRS on Form 8822-B. A responsible party change must be reported within 60 days.¹² The form has to be signed by an officer, owner, general partner, or LLC member-manager; a representative signing on behalf of the entity must attach a power of attorney such as Form 2848.¹³

Treat the EIN like a Social Security Number for the business: store it securely, limit access, use strong passwords on any system that holds it, and train employees to spot phishing. If you suspect your EIN is being misused, report it through the IRS business identity theft process.¹⁴

1
Massachusetts Department of Revenue. Tax Information for Businesses New to Massachusetts
2
Internal Revenue Service. Get an Employer Identification Number
3
U.S. Small Business Administration. Open a Business Bank Account
4
Mass.gov. Starting a Limited Liability Company (LLC) in Massachusetts
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Mass.gov. Starting a Corporation in Massachusetts
6
Internal Revenue Service. Responsible Parties and Nominees
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Internal Revenue Service. About Form SS-4, Application for Employer Identification Number (EIN)
8
Internal Revenue Service. Instructions for Form SS-4 (12/2025)
9
Internal Revenue Service. Employer Identification Number
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Massachusetts Department of Revenue. Register Your Business with MassTaxConnect
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Internal Revenue Service. When to Get a New EIN
12
Internal Revenue Service. About Form 8822-B, Change of Address or Responsible Party – Business
13
Internal Revenue Service. Form 8822-B, Change of Address or Responsible Party – Business
14
Internal Revenue Service. Identity Theft Information for Businesses