Process
Apply for EIN by Mail Guide
Mail Form SS-4 to IRS EIN Operation, Cincinnati OH 45999. Processing takes 4-6 weeks, the slowest EIN method. Fax is faster. ein.so files SS-4 by fax for $49.
Mail Form SS-4 to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999. Processing takes 4-6 weeks, the slowest EIN method. Non-US residents enter a passport number on Line 7b; no SSN or ITIN is needed. The IRS charges $0. Fax returns an EIN in 4-7 business days. ein.so files SS-4 by fax for $49 Standard or $97 Express.
Mailing Form SS-4 is the original paper route to a US Employer Identification Number. It still works in 2026, and it remains free from the IRS. It is also the slowest path by a wide margin. A mailed application takes 4-6 weeks of IRS processing, and that clock does not start until your envelope physically arrives in Cincinnati. For an applicant in Europe, Asia, or Latin America, international postage adds 6-21 more days before the IRS even opens the envelope. This guide gives the exact mailing address, the timeline, the SS-4 fields non-residents must complete, and the faster alternatives. ein.so prepares and faxes Form SS-4 so you skip the wait entirely.
| Factor | EIN by Mail |
|---|---|
| IRS address | Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999 |
| Form filed | Form SS-4 |
| IRS fee | $0 |
| Processing time | 4-6 weeks after receipt |
| Postage transit | 6-21 days |
| SSN required | No (passport on Line 7b) |
| Tracking | None from the IRS |
| Faster alternative | Fax — 4-7 business days |
Address
Where Do You Mail Form SS-4 to Get an EIN by Mail?
Mail Form SS-4 to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999. This is the only IRS address for international EIN applications by mail. No street number is required; the ZIP code 45999 routes the envelope to the EIN unit.
Non-US residents and applicants with no legal residence or principal place of business in the United States all use this single Cincinnati address. Domestic applicants with a US business address use a different IRS service center, but that case does not apply to most non-resident readers. Write the address exactly as shown, with "Attn: EIN Operation" on its own line, so internal IRS sorting routes the form to the correct desk.
Internal Revenue Service Attn: EIN Operation Cincinnati, OH 45999
International Postage Options
| Method | Cost | Transit Time |
|---|---|---|
| USPS / Postal First Class Int'l | $1.50-3 | 7-21 days |
| Postal Priority Int'l | $28-50 | 6-10 days |
| FedEx / DHL courier | $40-80 | 3-5 days |
Add 4-6 weeks of IRS processing after the envelope is delivered. A courier shortens transit but does not change the IRS processing window. See the full EIN application process and the EIN processing time breakdown for every method.
Comparison
How Does EIN by Mail Compare to Fax, Phone, and Online?
EIN by mail is the slowest of four IRS methods at 4-6 weeks, while fax returns an EIN in 4-7 business days and phone returns one the same day. The online tool is instant but requires an SSN, which blocks non-residents.
| Method | Speed | IRS Fee | SSN Required |
|---|---|---|---|
| Online | Instant | $0 | Yes — blocks non-residents |
| Phone | Same day | $0 | No |
| Fax | 4-7 business days | $0 | No |
| 4-6 weeks | $0 | No |
Mail is 6-10 times slower than every other route. The online tool is instant but unavailable to applicants without a Social Security Number. That leaves fax and phone as the practical fast options for non-residents. The IRS EIN fax number is 855-215-1627. ein.so files SS-4 by fax and delivers your EIN by email, which removes the postage transit and the 4-6 week wait. Read more in the EIN without SSN guide and EIN for non-residents.
Step-by-Step
How Do You Apply for an EIN by Mail as a Non-Resident?
Complete Form SS-4 with your passport number on Line 7b, then mail it to the IRS EIN Operation in Cincinnati, OH 45999. The IRS issues the EIN in 4-6 weeks and mails back the CP 575 confirmation letter. No SSN or ITIN is required.
Form Your US Entity
Gather Your Documents
Complete Form SS-4
Mail the Form to Cincinnati
Wait for the CP 575 Letter
Non-Resident SS-4 Field Guide
| SS-4 Field | Non-Resident Entry |
|---|---|
| Line 1 (Legal name) | Your US LLC or corporation name |
| Line 4 (Mailing address) | Your foreign home or business address |
| Line 7a (Responsible party) | Your full name as on your passport |
| Line 7b (SSN/ITIN/EIN) | Your passport number |
| Line 9a (Entity type) | LLC, corporation, or as formed |
| Line 10 (Reason for applying) | Started new business |
| Line 16 (Principal activity) | E.g., "software," "e-commerce," "consulting" |
The most common rejection cause for mailed forms is a malformed foreign address on Line 4. The IRS sometimes returns or shelves applications with addresses that do not fit the form layout. A wrong entry on Line 7b is the second-most common error. ein.so completes and faxes SS-4 to prevent both failures. See how to get an EIN for the complete process.
Use Cases
Who Should Use EIN by Mail Instead of Fax?
Use EIN by mail only when you have no access to a fax machine or fax service and you are not in a hurry. For every other non-resident, fax at 4-7 business days beats the 4-6 week mail wait. The form and the $0 IRS fee are identical for both.
No Fax Access
Not Time-Sensitive
Want a Physical Paper Trail
Everyone Else: Use Fax
After Approval
What Do You Do With Your EIN After It Arrives by Mail?
After the CP 575 letter arrives, use your EIN to open a US business bank account, connect payment processors, and meet your annual US tax filings. The EIN is the federal tax ID that links your foreign-owned entity to the US financial system.
Open a US Bank Account
File Form 5472 Annually
File Your BOI Report
Consider an ITIN if Needed
ein.so handles the EIN application and does not provide tax advice. Work with a US CPA familiar with non-resident matters to confirm your Form 5472, Form 1120, and BOI obligations. Your EIN is the starting point for US compliance, not the end of it.
Pricing
How Much Does an EIN by Mail Cost Versus ein.so?
An EIN by mail costs $0 from the IRS plus $1.50 to $80 in international postage. ein.so files SS-4 by fax for $49 Standard or $97 Express, removing the 4-6 week wait and the address-rejection risk. The IRS never charges for the EIN itself.
| Option | Cost | Delivery |
|---|---|---|
| DIY mail | $0 IRS + postage | 4-6 weeks + transit |
| DIY fax | $0 IRS | 4-7 business days |
| ein.so Standard | $49 | 4-7 business days |
| ein.so Express | $97 | 2-3 business days |
The cost difference between DIY mail and ein.so is the service fee for preparation, error checking, and fax filing. DIY mail saves the service fee but costs you 4-6 weeks and exposes the application to silent address rejections. See the full EIN cost breakdown for every method.
Next Steps
Get Your EIN Faster Than Mail
- Apply through ein.so — we file SS-4 by fax for $49 Standard or $97 Express
- Open a US bank account — Mercury, Relay, and Wise accept non-resident owners
- File your BOI report — required for most LLCs, free at fincen.gov/boi
- File Form 5472 — annually for foreign-owned LLCs ($25,000 penalty for non-filing)
- Review the basics — how to get an EIN, the SS-4 form guide, and EIN processing time
More guides: EIN without SSN | EIN for non-residents | EIN cost | EIN by fax | EIN by phone
Frequently Asked Questions
Where do I mail Form SS-4 to get an EIN?
Mail Form SS-4 to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999. This is the only IRS address for international EIN applications by mail. No street number is needed; the ZIP code routes the form. Domestic and foreign applicants without a US principal place of business use this same Cincinnati address.
How long does an EIN by mail take?
An EIN by mail takes 4-6 weeks from the date the IRS receives Form SS-4. This is the slowest of all four methods. Add 6-21 days of international postage transit before that window starts. Fax returns an EIN in 4-7 business days, so most non-residents choose fax over mail.
Does the IRS charge a fee for an EIN by mail?
No. The IRS charges $0 for an EIN by any method, including mail, fax, phone, and online. Your only cost for the mail method is international postage, which runs $1.50 to $80 depending on the carrier and speed you choose. ein.so files SS-4 by fax for $49 Standard or $97 Express.
Can non-US residents apply for an EIN by mail?
Yes. Non-US residents apply for an EIN by mail using Form SS-4 with their passport number on Line 7b. No SSN or ITIN is required. The IRS online tool requires an SSN and blocks non-residents, so mail and fax are the two paper routes. Fax is far faster at 4-7 business days.
Can I track my EIN application sent by mail?
Use certified mail or a tracked courier to confirm the IRS received your envelope. The IRS does not provide an application tracking number or status portal for mailed SS-4 forms. Call the IRS Business and Specialty Tax Line at 800-829-4933 only after 6 weeks pass with no EIN letter returned.
Should I apply for an EIN by mail or by fax?
Apply by fax. Fax returns an EIN in 4-7 business days; mail takes 4-6 weeks plus postage transit. The IRS EIN fax number is 855-215-1627. Both methods use the same Form SS-4. Use mail only when you have no fax access. ein.so handles the fax filing for $49.
What do I enter on Form SS-4 Line 7b as a non-resident?
Enter your passport number on Form SS-4 Line 7b. Non-US residents without an SSN or ITIN use the passport number to identify the responsible party. Write your full legal name as it appears on the passport on Line 7a. The IRS accepts passport identification for foreign responsible parties on every SS-4 method.
What does the IRS mail back after processing my SS-4?
The IRS mails back the CP 575 EIN confirmation letter to the address on Line 4 of your Form SS-4. This letter states your nine-digit EIN in the XX-XXXXXXX format. Banks accept the CP 575 to open an account. International return mail adds 1-3 weeks to the 4-6 week processing window.
Does a foreign-owned US LLC have to file taxes after getting an EIN?
Yes. A foreign-owned single-member US LLC files Form 5472 plus a pro-forma Form 1120 each year. The penalty for not filing is $25,000. Most US LLCs also file a BOI report with FinCEN. The EIN is the federal tax ID that links these filings. Confirm your obligations with a CPA.
Can ein.so help if I already mailed my SS-4 and got no response?
Yes. If 6 weeks pass with no EIN letter, ein.so can prepare and refile your Form SS-4 by fax to 855-215-1627. Fax delivers a result in 4-7 business days, far faster than restarting the mail process. Standard service costs $49 and Express costs $97 with delivery in 2-3 business days.
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