In the United States, whether you are filing taxes, working, starting a business, investing, or building a personal credit history, a Tax Identification Number (TIN) is an essential identity marker. Just like national ID, tax ID,and business registration codes in China, in the US each type of tax ID serves different purposes and applies to different scenarios.

The three most common tax IDs in the US are:

ITIN (Individual Taxpayer Identification Number) – for non-resident foreign individuals
SSN (Social Security Number) – for US citizens, green card holders, or individuals legally allowed to work
EIN (Employer Identification Number) – the federal tax ID used by companies and sole proprietors

Each of these tax IDs serves a distinct audience and supports unique tax, identity, and financial functions. Below is an in‑depth explanation of their differences, eligible users, practical uses, and application methods to help you quickly build a complete understanding of the US tax ID system.

1. ITIN: The Personal Tax ID Designed for Foreign Individuals,What is an ITIN?

An ITIN is a tax ID issued by the IRS for non-US residents or foreign individuals who are not eligible for an SSN but are required to file US taxes. Simply put, ITIN application provides a legitimate way for those without SSN eligibility to report income, receive payments, or open a bank or credit account in the U.S.

If you are not a US citizen, live outside the US,have no green card or work visa,but have any of the following situations, you need to apply for an ITIN:

You earn US income through cross-border e-commerce platforms (like Amazon, eBay, Etsy) and need to file taxes
You own US real estate and receive rental income or capital gains
You are a spouse or child on F2, J2 visa needing inclusion on tax filings
You want to open a US bank account or apply for a loan without an SSN
You wish to trade US stocks and need a US brokerage account
You want to benefit from US – China tax treaty relief
You are a foreign student, researcher, or other special case requiring US tax filing

Common Uses of ITIN

Filing US personal income tax returns (such as 1040-NR)
Applying for online merchant payment gateways like Stripe, Square, or PayPal-all often require ITIN usage
Opening a US bank account or applying for a credit card (some banks accept ITIN)
Proving US residency for mortgage, auto loan, or driver’s license applications
Supporting legal investment and financial management in the US
Note: ITIN is solely for tax identification-it does not authorize lawful employment nor provide eligibility for US social benefits.

How to Apply for an ITIN- There are two main routes:

Self‑mail submission (lower cost, longer processing time):Download and fill out IRS Form W‑7;Prepare passport, birth certificate, visa, and identity documents;Mail everything to the IRS designated address;Processing typically takes 9 to 18 weeks, with risks of loss or return of documents;Apply via IRS‑authorized CAA (Certified Acceptance Agent) – Recommended

For faster, secure, and compliant ITIN application- We provide full remote review and verification of IDs;No need to mail original documents;Efficiency improved—application time reduced by 50–70% on average.Want to know more about ITIN application process, how to apply ITIN, or how long ITIN application service takes? Contact us for one-on-one CAA service plans.

2. SSN: The Core of Identity and Credit for US Residents

SSN, short for Social Security Number, is assigned by the US government to citizens, permanent residents, and individuals with legal work authorization. It’s not only used for tax filing but also tracks an individual’s tax history and underpins credit, identity, welfare, and more,similar to China’s national ID number. For anyone living and working in the US, an SSN is indispensable; it runs through the entire spectrum of financial and credit life in America.

Eligible individuals for SSN:U.S.-born or naturalized citizens、Permanent residents (green card holders)、Holders of legally working visas (e.g. H1B, OPT for F1 students)

Common use cases:

Employment: employers require SSN for payroll and tax reporting
Building credit: applying for credit cards, loans, and housing
Tax and welfare applications: annual tax return filing, social security, healthcare benefits
Government and bank registrations: medical, driver’s license, and government services often require SSN

How to apply:
Visit your local Social Security Administration (SSA) office, submit your passport, visa, school or employer verification documents, fill in the application form, attend an interview, and receive your SSN card by mail in around 2 weeks.
3. EIN: The Identity Number for US Business Operations

What is an EIN?EIN,or Employer Identification Number, is the official federal tax ID assigned by the IRS to businesses and organizations in the US Once your company is registered, the first essential step is to obtain an EIN- without it, you cannot operate officially, open bank accounts, or file taxes.

Who Needs an EIN?

Businesses such as LLCs, C-Corps, S-Corps, sole proprietorships, and non-profit organizations require EINs. Especially if you:

Sell on platforms like Amazon, eBay, or Walmart;Have employees requiring payroll and tax processing;Require state tax IDs or sales tax permits;Are a foreign company opening a US bank account or filing income

Uses of EIN

Business tax filing and annual corporate reports
Opening business bank accounts
Registering payment platform accounts (Stripe, PayPal, etc.)
Hiring employees and handling payroll taxes
Commercial activities including customs clearance, contract signing, trademark registration

How to Apply for an EIN

US persons with SSN can apply online for free via the IRS website
Non-US residents without SSN can use professional service providers (we offer remote E‑service- EIN issued in 1–2 business days)
Mailing application takes about 1–4 weeks

Important: Even if your company is not actively trading, you must file zero‑income returns on time to avoid IRS fines or blacklisting.The Right Tax ID Unlocks Your Path to Compliance

Starting with ITIN application, progressing to SSN-based credit buildup, and eventually using an EIN to conduct business- these three US tax identification numbers are more than mere identity codes; they are the keys to legitimate access to the US commercial system.

For many of our clients in China and abroad, ITIN is often the very first step in cross-border expansion, tax compliance, and investment. If you are considering US e-commerce operations, applying for tax IDs, or registering a company, we offer a full-service solution:

ITIN application and assistance (IRS-authorized CAA service)
US company formation in all 50 states + DC with free EIN, real US business address, local agent service, mail scanning, company bylaws, and business license delivery;Full compliance support including corporate tax filing, annual reports, and business bank account setup

📞 Shenzhen GuanSai Technology Co., Ltd. – 15 years of US corporate services experience, safeguarding your journey!