How to Fill Out Form SS-4 for an Estate: Lines, Filing, and EIN

To fill out Form SS-4 for an estate, enter the estate’s legal name on Line 1, the fiduciary’s name on Line 3, the fiduciary’s identifying information on Lines 7a and 7b, check the “Estate” box on Line 9a and add the decedent’s Social Security Number, write “Created a decedent’s estate” on Line 10, put the date of death on Line 11, and mark the LLC, employment, and incorporation lines “N/A.” The rest is address and tax-year detail. Below is what each line needs, what to skip, and the one line that actually calls for a decision.

What to Gather Before You Start

Missing any of these will stall the application:

The estate’s legal name, typically “Estate of [Decedent’s Full Name], Deceased,” matching the probate order or will.¹
The fiduciary’s full legal name and title (executor, administrator, or personal representative).
The fiduciary’s SSN or ITIN. A non-resident fiduciary with neither enters “foreign” on Line 7b.²
The decedent’s SSN or ITIN (needed on Line 9a).
The date of death.
The closing month of the estate’s tax year (see the calendar-vs-fiscal section below).

Line-by-Line Instructions

Lines 1 Through 6: Names and Address

On Line 1, enter the estate’s full legal name exactly as it appears in the probate documents.¹

Line 2 (trade name) does not apply to estates. Enter “N/A.”

Line 3 asks for the executor, administrator, trustee, or “care of” name. Put the fiduciary here. This is the person the IRS will contact about the estate’s tax account, so do not leave it blank.¹

Lines 4a and 4b take the mailing address where you want IRS correspondence sent. Because Line 3 is filled in, use the fiduciary’s mailing address.¹

Lines 5a, 5b, and 6 ask for a street address if it differs from the mailing address, plus the county and state where the estate is located. If they are the same, enter “N/A” on 5a and 5b and complete Line 6 with the county and state.

Lines 7a and 7b: Responsible Party

Enter the fiduciary’s full legal name on Line 7a and their SSN, ITIN, or existing EIN on Line 7b. This identifies you personally as responsible for the estate’s tax obligations, and it is separate from the EIN you are applying for.¹

When co-executors have been appointed, only one is listed as the responsible party, and only one signature is required. The IRS instructions call for “the fiduciary” to sign, not all fiduciaries.¹

Lines 8a Through 8c: LLC Questions

These apply only to limited liability companies. Enter “N/A” and move on.

Line 9a and 9b: Entity Type

On Line 9a, check the box labeled “Estate (SSN of decedent)” and write the decedent’s SSN or ITIN in the space next to it. Leaving that number blank is one of the most common causes of processing delay.¹

Leave Line 9b blank. Estates are not incorporated.

Line 10: Reason for Applying

Check “Other” and write “Created a decedent’s estate.” The other reasons on this line (starting a business, hiring employees, creating a trust) do not describe what is happening.¹

Lines 11 and 12: Dates and Tax Year

On Line 11, enter the decedent’s date of death. This is the estate’s start date for tax purposes.¹

On Line 12, enter the closing month of the accounting year. Most estates put “December.” If you plan to elect a fiscal year, enter that month instead. The next section explains the tradeoff.

Lines 13 Through 17: Employees and Activity

Lines 13 through 16 cover employees and payroll taxes. Unless the estate is continuing a business the decedent operated and that business has employees, enter “N/A” or zero.

On Line 17, describe the principal activity. Something like “Administration and distribution of a decedent’s estate” or “Settlement of estate” works.¹

Line 18 and Signature

If an attorney or accountant is filing on your behalf, use Line 18 to name them as third-party designee and give their contact information. The authorization is limited to the EIN application and does not extend to other tax matters.³

Sign and date at the bottom. Fiduciary signature, title, and phone number are all required.

Calendar Year or Fiscal Year on Line 12

This is the one line on Form SS-4 that involves real judgment. A calendar year (closing month December) makes Form 1041 due April 15. A fiscal year can push the first filing deadline further out, because Form 1041 is due on the 15th day of the fourth month after the close of the tax year.⁴ If the decedent died in March and you elect a fiscal year ending in February, the first return is not due until June 15 of the following year.

Two constraints. The first tax year cannot exceed 12 months from the date of death, so the month you pick on Line 12 must fall within that window. And once the election is made, it applies for the estate’s entire existence.

How to Submit Form SS-4

You have three filing channels, and the speed difference is significant.

Online

The IRS EIN Assistant at irs.gov walks you through an interview version of the form and issues the EIN on screen when you finish. Two limits: only one EIN per responsible party per day, and the tool is only available if the applicant has a legal residence or principal office in the United States or its territories.⁵

Fax

Applicants in the 50 states or the District of Columbia fax the signed form to 855-641-6935.⁶ Include a return fax number for the confirmation. Processing generally takes about four business days. From outside the United States, the fax number is 304-707-9471; from a U.S. territory, 855-215-1627.²

Mail

Send the signed form to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999. Expect four to five weeks for the confirmation to arrive by return mail.⁶

Fiduciary Outside the United States

A fiduciary with no legal residence, business, or office in the United States or its territories cannot use the online tool. Apply by phone at 267-941-1099, Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern. The caller must be authorized to receive the EIN and answer questions about the form.²

After the EIN Is Assigned

The IRS mails Notice CP 575 confirming the number. Banks and brokerage firms typically want to see this notice before opening estate accounts. The EIN is permanent and appears on every Form 1041 the estate files until it is formally closed.⁷

If you lose the notice, 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. After identity verification, the IRS confirms the EIN by phone and issues a replacement called Letter 147C.⁸ The number also appears on any previously filed Form 1041 and on bank correspondence for the estate.

If a successor fiduciary takes over the estate, the new responsible party must file Form 8822-B within 60 days to update IRS records.⁹ Skipping that filing can lock the new fiduciary out of IRS communications when the next return comes due.

1
Internal Revenue Service. Instructions for Form SS-4
2
Internal Revenue Service. Instructions for Form SS-4 (12/2025)
3
Internal Revenue Service. Form SS-4 (Rev. December 2025)
4
Internal Revenue Service. Forms 1041 and 1041-A: When to File
5
Internal Revenue Service. Get an Employer Identification Number
6
Internal Revenue Service. Where to File Your Taxes for Form SS-4
7
Internal Revenue Service. About Form SS-4, Application for Employer Identification Number (EIN)
8
Internal Revenue Service. Employer Identification Number
9
Internal Revenue Service. Form 8822-B Change of Address or Responsible Party — Business