Plain-language glossary

EIN

A nine-digit number the IRS gives your company — an ID number for the business. You need one to open a US bank account, use Stripe or PayPal, sell on Amazon, or file anything with the IRS. The number itself is free from the IRS.

Form SS-4

The application form for an EIN — 18 sections, about 35 fields. Without a US Social Security Number you cannot use the IRS website and must send this form by fax or post instead.

CP-575

The letter the IRS posts to confirm your EIN. Banks and payment providers often ask to see it. It goes to the mailing address on the application. A reliable, authorised US address is recommended; foreign addresses are allowed.

147C letter

A replacement confirmation. If you lose the CP-575 the IRS will not reissue it; it sends a 147C letter instead, which banks accept in the same way.

Form 5472

An information report of related-party transactions. A foreign-owned US disregarded entity generally files it when reportable transactions occurred. No revenue alone does not remove the requirement; missing a required filing can cost $25,000 or more.

Form 1120

Form 1120 is the US corporate tax return. Your LLC does not really file one, but Form 5472 has to be attached to something — so a nearly empty (“pro forma”) 1120 is used as its cover page.

Form 7004

A request for more time to file, moving the deadline from April 15 to October 15. It must reach the IRS before April 15, and it postpones the filing, not a payment.

Responsible party

The real person who controls the company — you. The IRS requires a human being here, not an agency and not a company name.

Disregarded entity

How the IRS treats a single-owner LLC: the company and its owner are one taxpayer unless corporate taxation was elected. The LLC generally is not a separate federal income taxpayer; owner tax obligations and Form 5472 reporting need separate checks.

FTIN

Your tax number in your own country — for example a Chinese taxpayer number or a UK UTR. Form 5472 asks for it. It is not a US number.

Form 1040

The income tax return filed by US citizens and US tax residents. If you are neither, this is not your form.

Form 1040-NR

The US personal tax return for non-residents. You file it only if you have US income the US can tax — which most foreign-owned LLCs with overseas customers do not.

ITIN

A US tax number for individuals who cannot get a Social Security Number. You do not need one to get an EIN for your company.