The good news, getting an Employer Identification Number is straightforward once you understand Form SS-4, what the IRS expects, and which filing route actually fits your situation.
If you need your EIN today, apply online during IRS service hours and download the confirmation immediately. This is the fastest path for most U.S. based applicants.
Key Takeaways
- Form SS-4 is how you apply for an EIN to identify your business for taxes, payroll, banking, and licenses.
- The fastest route is the IRS online EIN application, available Monday to Friday, 7 a.m. to 10 p.m. Eastern, with instant issuance once you finish. There is a one EIN per responsible party per day limit.
- If you cannot file online, you can fax or mail Form SS-4. Fax responses usually arrive in about 4 business days, mail takes around 4 weeks.
- Keep the EIN confirmation in your permanent records and use Form 8822-B to report address or responsible party changes within 60 days.
- International applicants who are not eligible for the online tool can apply by phone at 267-941-1099, typically Monday to Friday, 6 a.m. to 11 p.m. Eastern.
What Form SS-4 Does, In Plain English
Form SS-4 is the short IRS application that creates your business tax identity, your EIN. Banks ask for it, payroll providers require it, and it helps you keep business and personal finances separate. You will share your legal name, any trade name, addresses, entity type, the responsible party’s taxpayer ID, your start date, expected employees, and your principal activity. The IRS uses that data to issue your EIN and connect future filings to your account.
If you qualify for the online assistant, you can apply and get your number in minutes during IRS service hours. If you cannot, fax or mail works, and international applicants can apply by phone with the IRS.
Who Actually Needs an EIN
You need an EIN if you are forming a corporation or partnership, running a multi member LLC, administering a trust or estate, or operating a nonprofit. Hiring employees flips the switch as well, even for a sole proprietor. Many single member LLC owners also get an EIN to avoid using a Social Security Number with vendors and banks.
Two useful rules of thumb:
- If you are paying wages, plan payroll deposits or Forms W 2, get the EIN before the first payroll.
- If your entity structure or ownership changes, check whether you need a new EIN, and when you must update the responsible party. The IRS outlines change triggers and responsible party rules clearly.
The Responsible Party, Keep This Detail Tight
The IRS wants the person who ultimately controls the entity and its assets, the responsible party, not a nominee. You will enter that person’s legal name and SSN, ITIN, or EIN on the application. If you listed a nominee in the past, correct it. If your responsible party changes later, file Form 8822 B within 60 days to keep your records clean and your notices going to the right place.
A quick note on timing and limits
- Online availability is Monday to Friday, 7 a.m. to 10 p.m. Eastern.
- The IRS caps issuance at one EIN per responsible party per day. Plan your incorporations and bank appointments around these guardrails.
Why This Matters For Firms And Founders
If you are a founder, your bank onboarding, payroll setup, and sales tax registration often wait on your EIN. If you run an accounting firm, the EIN step can clog onboarding when staff are buried in other production work. On our side, we keep the EIN step inside a documented checklist so there is no scramble on bank day and no rework when addresses or responsible parties change later. If you follow the steps below, you will avoid the common stalls and keep momentum.
Note for readers from accounting firms, Accountably supports client onboarding workflows where Form SS-4 prep, submission tracking, and 8822 B updates sit inside a controlled delivery process. Use it where it helps, or follow the same structure with your in house team.
What You Need Before You Apply
Gather this once, apply once, move on. Having complete data stops mid application timeouts and prevents mismatches that delay banking.
Required info checklist
- Identity details, legal name, trade name, formation state, and date.
- Responsible party, full name plus SSN, ITIN, or EIN, and a reliable daytime phone.
- Addresses, mailing and physical location, city, county, state.
- Operational profile, principal business activity and a short description of your product or service, accounting closing month, reason for applying, and the business start date.
- Employment data, highest expected number of employees over the next 12 months, by category if relevant, and the first date wages will be paid, or N A if none.
Tip, if a tax pro will submit for you, decide whether to authorize them as a third party designee on the form so they can receive the EIN and talk to the IRS about your application.
Step by Step, Completing Form SS-4
Follow the form from the top down, and you will be done in minutes.
- Lines 1–2, legal name and any DBA.
- Lines 4–5, mailing and physical addresses, do not use a P O Box for the physical location.
- Line 6, county and state.
- Line 7, responsible party and their SSN, ITIN, or EIN.
- Lines 8–12, entity details, reason for applying, start date, and closing month.
- Lines 13–17, expected employees, first payroll date if any, business activity code, and a short description of what you do.
If you will use a third party designee, complete that section, sign, and date. For international phone applications, it helps to complete SS 4 ahead of time so you can read each answer as the agent sets up your account. The IRS instructions confirm this approach and it makes the call faster.
Responsible party, common mistakes to avoid
- Do not list a nominee. The IRS requires the person who actually controls the entity, and they are strict on this point.
- Update changes quickly with Form 8822 B, address or responsible party changes must be reported within 60 days.
What Happens After You Submit
- Online applicants receive the EIN on screen and can download the confirmation immediately during IRS service hours.
- Fax applicants generally receive a faxed reply in about 4 business days. Include your return fax number or you will wait longer.
- Mailed applications take about 4 weeks.
- Domestic applicants do not receive EINs by phone, only international applicants can apply by phone.
Keep the confirmation in your permanent records. Your bank, payroll provider, and state agencies will ask for it, sometimes more than once.
The Data Table You Will Thank Yourself For Later
Create a simple one pager you can re use for banks, payroll, and state registrations.
| Field | Your Entry | Where It Appears |
| Legal name and DBA | SS-4 Lines 1–2 | |
| Responsible party + TIN | SS-4 Line 7 | |
| Mailing and physical address | SS-4 Lines 4–5 | |
| Start date and reason | SS-4 Lines 10–11 | |
| Closing month | SS-4 Line 12 | |
| Employees and first payroll date | SS-4 Lines 13–15 | |
| Principal activity and description | SS-4 Lines 16–17 |
Keep this with your formation papers and the EIN confirmation. It becomes your “single source of truth” for every downstream form.
Filing Options, Speed, And What To Expect
Choosing the right filing method is about speed and eligibility. Here is a clear comparison you can use with your team or your client.
EIN filing options compared
| Method | Who can use it | Typical timing | What you get |
| Online application | U.S. address or territory, responsible party has SSN, ITIN, or EIN | Immediate during IRS hours, Monday to Friday, 7 a.m. to 10 p.m. Eastern | EIN issued on screen, confirmation to download |
| Fax submission | Anyone who cannot use the online assistant | About 4 business days if you include a return fax number | Faxed EIN assignment |
| Mail submission | Anyone who cannot use online or fax | About 4 weeks | Mailed EIN assignment |
| Phone, international only | Principal place of business outside the U.S. | Same day during call hours, Monday to Friday, 6 a.m. to 11 p.m. Eastern | EIN assigned during the call |
The hours, processing timelines, and daily issuance limit come straight from current IRS guidance. Domestic phone assignments are no longer available, only international applicants can receive an EIN by phone.
Addresses and fax numbers, current as of December 3, 2025
| Location | Where to send SS-4 |
| U.S. based applicants | Internal Revenue Service, Attn, EIN Operation, Cincinnati, OH 45999, Fax 855 641 6935 |
| International or no U.S. location | Internal Revenue Service, Attn, EIN International Operation, Cincinnati, OH 45999, Fax 855 215 1627 within the U.S., or 304 707 9471 outside the U.S. |
Keep in mind, the IRS confirms these details in its “Where to file” guidance and in the SS 4 instructions. If you provide a fax number, they will fax your EIN back.
Use only one submission method. Sending duplicates by fax and mail can slow things down instead of speeding them up.
How To File Online Without Hiccups
- Check eligibility, U.S. address or territory, responsible party with SSN, ITIN, or EIN.
- Gather all data first, the session can time out after inactivity, and you cannot save and return later.
- Apply during service hours, Monday to Friday, 7 a.m. to 10 p.m. Eastern.
- Download the PDF confirmation immediately and save it to your permanent records folder.
Practical tips from the field
- Calendar your bank appointment after the EIN window, not before.
- If your firm onboards many entities in one day, remember the daily limit of one EIN per responsible party. Stagger filings to avoid the cap.
- If a remote owner cannot provide an SSN or ITIN yet, consider whether you qualify for the international phone route or plan for fax or mail with a complete SS-4.
When Fax Or Mail Is The Right Call
Fax is the best fallback if you cannot use the online tool. Include a clear return fax number on the form. Expect about 4 business days if everything is complete. Mail is reliable when fax is not available or for records driven workflows, it usually takes about 4 weeks. The IRS confirms these timeframes in the official instructions and on taxpayer assistance pages.
Third Party Designee, Limited Authority That Helps
If you want a tax professional to apply for your EIN, name them as a Third Party Designee on Form SS-4. This gives them permission to talk with the IRS about your application and receive the EIN. Their authority ends once the number is issued, which keeps control with you. This is helpful when a founder is traveling or when a firm builds EIN intake into a larger entity setup. The IRS instructions and taxpayer resources both outline this option clearly.
Keep Your EIN Clean, Records And Updates
Treat the EIN confirmation as a permanent record. File it with your formation documents, store it in your secure drive, and note every system that uses it, bank accounts, payroll, state portals, and tax returns. If something changes, update the IRS fast.
- Use Form 8822 B to report address changes or a new responsible party, the deadline is within 60 days.
- If you misplace your EIN, check bank records, prior returns, and agency accounts first, then call the Business and Specialty Tax Line at 800 829 4933 for verification if needed.
- Keep your designee list tight to reduce exposure of sensitive identifiers.
Nominees, why they create problems
A nominee is not your responsible party. If you list a nominee, you risk misdirected notices and you will need to correct the record. The IRS is explicit that nominees cannot apply, and they should not be listed on Form SS 4. If this happened, fix it with Form 8822 B and use the true responsible party going forward.
Compliance Corner, What Changed And What To Watch
- Domestic EINs are no longer assigned by phone, only international applicants can use the phone method.
- Online service hours, the 7 a.m. to 10 p.m. Eastern window is still current for 2025.
- The one EIN per responsible party per day limit remains in effect, plan multi entity days accordingly.
- Addresses and fax numbers for the Cincinnati EIN Operation are current as of December 3, 2025.
Form SS-4, where to send and how fast to expect a reply
- U.S. applicants, mail to Cincinnati 45999 or fax 855 641 6935.
- International applicants, mail to the International Operation in Cincinnati or fax 855 215 1627 inside the U.S., or 304 707 9471 from outside the U.S.
- Fax replies generally take about 4 business days, mail about 4 weeks.
Small teams often stall here because no one owns the follow up. Assign one owner to confirm receipt and save the EIN confirmation the same day it arrives.
Where Accountably Fits, Only If You Need It
If you are an accounting firm buried in onboarding and compliance, you can fold SS 4 prep, submission tracking, and 8822 B updates into a standardized workflow. Accountably integrates this step inside a documented delivery process, which means fewer last minute scrambles on bank day and cleaner records later. If you already have a strong process, keep going, the steps in this guide are everything you need.
FAQs, Fast Answers To Common SS-4 Questions
Can I complete Form SS-4 online and get my EIN today
Yes, if you meet online eligibility and apply during IRS hours, Monday to Friday, 7 a.m. to 10 p.m. Eastern, you receive the EIN immediately and can download the confirmation. There is a limit of one EIN per responsible party per day.
I am a non U.S. owner with no SSN or ITIN, how do I get an EIN
If your principal place of business is outside the U.S., call the IRS at 267 941 1099 during the posted hours to apply by phone, or submit a completed SS 4 by fax or mail to the International Operation.
How long does it take if I fax or mail Form SS-4
Faxed applications typically receive a response in about 4 business days when you include a return fax number. Mailed applications take about 4 weeks.
I lost my EIN, how do I find it
Check bank records, state and local agency accounts, and prior returns. If you still cannot find it, call the Business and Specialty Tax Line at 800 829 4933 during business hours for verification.
Do single member LLCs need an EIN
Many single member LLCs use an EIN for banking and vendor paperwork, and you must have one if you will hire employees or file certain federal taxes. If your ownership or structure changes, review whether you need a new EIN.
When must I file Form 8822 B
File Form 8822 B within 60 days of any address or responsible party change to keep your IRS account current and avoid missed notices.
Common Pitfalls And How To Avoid Them
- Listing a nominee instead of the true responsible party, correct with 8822 B and use the right person going forward.
- Forgetting the online hours or the daily issuance limit, which turns a same day plan into a wasted trip to the bank.
- Faxing without a return number, which adds days for a mailed reply.
- Submitting by multiple methods, duplication can delay processing.
Final Checklist, Ready To File
- Data gathered and verified, names, addresses, responsible party ID, start date, activity, employees.
- Form SS-4 completed and, if needed, third party designee section filled.
- Filing route selected, online if eligible and urgent, fax if not, mail if neither fits.
- Calendar reminders set, save EIN confirmation to permanent records, note where the EIN is used.
- Update plan in place, file 8822 B for responsible party or address changes within 60 days.