Common EIN Application Mistakes (and How to Avoid Them)

Line 10 of Form SS-4 asks why you're applying for an EIN, with options like 'Started new business,' 'Banking purpose,' 'Changed type of organization,' and others. Selecting an overly generic reason, or leaving detail fields blank when a specific NAICS business activity code is requested, can slow processing since it gives the IRS less to work with when validating the application. Being specific here -- correct reason, correct NAICS code matching your actual business activity -- speeds things up rather than adding complexity. If you're genuinely unsure which NAICS code fits, a close approximate match is far better than leaving the field blank or picking an unrelated code just to fill the space.

An EIN identifies your business entity to the IRS; an ITIN or SSN identifies an individual. These are separate systems that serve different purposes, and having one doesn't require or substitute for the other. A non-resident founder does not need to obtain a personal ITIN before applying for their LLC's EIN -- this is a common point of confusion, since some other countries' business registration processes do require a personal tax ID before a business ID can be issued. In the US system, you can get your LLC's EIN with no personal US tax ID at all, using 'Foreign' as your responsible-party designation.

The IRS's online EIN application is genuinely faster (immediate issuance) but is only available to applicants with a US SSN or ITIN. Non-resident founders without either must apply by fax or mail -- there's no way around this, and attempting the online form as a non-resident without a qualifying ID typically results in the application simply failing partway through rather than completing. Some founders try repeatedly on the online portal before realizing the eligibility restriction, losing time they could have spent preparing the correct fax application instead.

This is the single most common mistake we see across founders from dozens of countries: entering a home-country ID number (a national ID, passport number, or tax ID) into the field meant to identify the responsible party, instead of selecting 'Foreign' as instructed for applicants without a US SSN or ITIN. The IRS processes SS-4 forms partly by matching ID fields against expected formats -- a passport or national ID number entered where a 'Foreign' designation belongs doesn't match, and the IRS mails back a rejection notice rather than emailing a correction request, adding real weeks to your timeline since mail correspondence with the IRS is slow in both directions.

Once issued, your EIN confirmation arrives as an IRS Notice CP575 -- this letter is often the only official proof of your EIN that banks, payment processors, and other institutions will accept during onboarding. Founders occasionally misplace this letter and then struggle to prove their EIN when opening a bank account, since the IRS's process for requesting a replacement letter (Form 147C) takes additional time and, for non-resident applicants, may itself require a phone call to an IRS international line during specific hours rather than a simple online request. Save a digital and physical copy the moment it arrives, and store it somewhere you'll actually find it again -- a dedicated folder in cloud storage works better than an email inbox you might switch away from.

The legal name and formation date on your SS-4 must exactly match your state-approved formation documents (articles of organization or certificate of formation). A common error is applying for the EIN using a shortened or informal version of the business name, or guessing at the formation date before the state has actually approved and dated the filing. Wait for your state approval confirmation before filing SS-4, and copy the legal name and date exactly as they appear on that document -- including punctuation like commas before 'LLC' if your state's approved filing includes them.

Fax is the standard method for non-resident applicants without SSN/ITIN, and the IRS doesn't send an instant confirmation the way email would. Founders sometimes assume a fax failed and resend duplicate applications days apart, which can create confusing duplicate processing on the IRS side and, in some cases, two separate EINs issued for the same entity, which then requires a call to the IRS to consolidate or void the extra one. The realistic timeline is 4-7 business days after successful fax transmission before you hear back -- worth building that into your planning rather than assuming something went wrong if you don't hear back within a day or two.

Some founders enter their registered agent's address in the SS-4's mailing address field, assuming that's the correct 'official' address for the business. The mailing address field is actually where the IRS will send your CP575 confirmation letter and any future correspondence -- if that's your registered agent's address rather than an address you personally monitor, you may not see IRS mail promptly. Many founders instead use a virtual mailbox or forwarding address they check regularly, keeping the registered agent's address strictly for its intended legal-notice purpose.