What to Do After Receiving Your EIN Letter

The EIN letter from the IRS is one page. It looks like a routine government notice — and technically it is. But the nine-digit number on that page is what turns your LLC from a filed document into an operating business. Banks require it. The IRS expects it. Your accountant will ask for it on day one. Here is exactly what to do the moment it arrives.

What the EIN letter actually is

The official name is the CP575 notice. It is issued by the Department of the Treasury, Internal Revenue Service, and it confirms that your LLC has been assigned an Employer Identification Number.

Your EIN looks like this: XX-XXXXXXX (two digits, a hyphen, seven digits). It is your business's tax ID — the equivalent of a Social Security Number, but for your LLC.

If you used a virtual address like UseStable, they will receive the physical letter at your registered address, scan it, and email you a PDF. You do not need to be physically present in the US. If you gave a personal or office address, check your physical mailbox. The letter typically arrives 4 to 6 weeks after your LLC formation is complete.

Step 1 — Verify every detail is correct

Before you do anything else, read the letter carefully. Check:

• Your LLC name — it should match exactly what you filed with the state and Stripe Atlas.
• The EIN format — two digits, hyphen, seven digits (e.g., 87-1234567). Note it somewhere secure.
• The address on file — this is where the IRS will send future mail.
• The entity type — should say "Limited Liability Company" or similar.

Step 2 — Scan it and store it permanently

The minute you have the letter — scan it or save the PDF from UseStable. Then:

1. Upload to Google Drive or Dropbox in a dedicated "LLC Documents" folder.
2. Name the file clearly: EIN-Letter-[YourLLCName]-2025.pdf
3. Email yourself a copy as a backup.
4. If you received a physical letter, store the original in a physical folder with your other LLC documents.

You will reference this document repeatedly: when your accountant onboards you, when you apply for business credit, when you open additional bank accounts, and every tax filing season.

Step 3 — Update your Mercury bank account

Mercury lets you open a business bank account before your EIN letter arrives — which is useful for getting your account number early. But once the letter lands, you need to complete the EIN verification step.

1. Log in to your Mercury account at mercury.com.
2. Navigate to Account settings → Documents or follow any pending verification banner.
3. Upload your EIN letter (the CP575 PDF).
4. Mercury reviews it, typically within 1-2 business days.

Once verified, any temporary restrictions on your account are lifted and your account is fully operational. If you have not opened a Mercury account yet, do it now — it is the bank most international founders use for their U.S. LLC.

Step 4 — What your EIN now unlocks

Your EIN being confirmed opens up the practical infrastructure of your LLC. Here is what you can now do:

Business credit

Apply for a business credit card. Mercury offers a secured business credit card — you fund it with a deposit and it builds your business credit history. This is especially useful for international founders who do not have a U.S. personal credit score. Your business credit score starts at zero; the sooner you start building it, the better.

Tax filing

A single-member LLC is a disregarded entity by default — the IRS taxes your LLC income on your personal return (Schedule C in the U.S.). Even if your LLC had zero revenue in its first year, you may still need to file. Talk to a CPA familiar with international founder situations — filing requirements depend on your residency, where income was earned, and your home country's tax treaties with the U.S.

Delaware franchise tax (if you formed in Delaware)

Delaware LLCs owe an annual franchise tax, due June 1 each year. For most small LLCs, this is a flat $300. You can calculate and pay it at the Delaware Division of Corporations website. Your EIN is not required for this payment — but having it handy keeps your records consistent.

ITIN application (international founders)

If you are a non-U.S. resident without a Social Security Number, you may need an Individual Taxpayer Identification Number (ITIN) to file a U.S. tax return personally. The application is IRS Form W-7 and typically requires a certified copy of your passport. Your LLC's EIN and formation documents support the application. A CPA or Certified Acceptance Agent (CAA) can process this for you.

Stripe and other payment processors

If you formed through Stripe Atlas, your Stripe account is already connected to your LLC. Check your Stripe dashboard — your EIN should already be on file from the formation. If anything needs updating (or if you set up Stripe independently), go to Settings → Business settings → Tax details and enter your EIN.

If your EIN letter has not arrived yet

Standard timeline is 4-6 weeks. If you are past that:

1. Check your virtual address dashboard (UseStable) — the letter may already be there, scanned and waiting.
2. Check your Stripe Atlas dashboard — Stripe often records your EIN in the formation documents even before the physical letter arrives.
3. If neither has it, call the IRS Business & Specialty Tax Line: 800-829-4933 (Mon-Fri, 7am-7pm local time).

When you call, have ready:

• Your LLC's legal name (exactly as filed)
• Your LLC's registered address
• The date your LLC was formed
• Your name (as the responsible party on the application)

The IRS can give you a verbal EIN confirmation over the phone, which you can use immediately for most purposes. They can also send a replacement notice (Letter 147C): by fax, same day; or by mail in 10-14 business days to your address on file. Request the fax option if you need it urgently.

CP575 vs. Letter 147C — what is the difference

Two different documents, same purpose:

• CP575 — the original EIN confirmation. Mailed automatically when your EIN is first assigned. The IRS sends this only once.
• Letter 147C — a replacement confirmation you can request anytime by calling the IRS. Takes 10-14 business days to arrive by mail, or they can fax it the same day.

Both are accepted by banks, accountants, state agencies, and the IRS itself as valid proof of your EIN. If you ever lose the CP575, a 147C is a perfect substitute. There is no need to panic about the original — just store it well from day one and you will never need to replace it.

You are more operational than you realize

Getting your EIN letter is one of those milestones that feels administrative but is actually the moment your LLC becomes fully real. Your bank account is verified. Your tax ID is confirmed. Your Stripe account is linked. Your compliance calendar starts ticking.

The next steps — LLC taxes, compliance, and building your online presence — are covered in the rest of the guide. Head back to the main page to continue.