An ITIN —Individual Taxpayer Identification Number— is the number the IRS issues to people who must file taxes in the United States but cannot get a Social Security number. It does not grant work authorization, it does not change your immigration status and it is not an ID. It does one very specific thing: it makes you exist to the tax system.
Plenty of people pay between $300 and $600 for a process they could complete themselves. This guide walks through all of it.
Who needs one
You need an ITIN if any of these apply:
- You have US income and must file a tax return.
- You are the dependent or spouse of someone filing who wants to claim you.
- You receive income with tax withheld: bank interest, scholarships, royalties.
- You are opening an LLC and need to identify yourself to the IRS.
If you already have a Social Security number you cannot apply for an ITIN. And if you get an SSN later, you must tell the IRS so it merges your tax history.
The three documents you need
1. Form W-7
The application itself. Two pages. The mistakes that get it returned most often:
- Ticking the wrong reason box at the top. Most people need b (nonresident alien filing a return) or d (dependent).
- Writing your name differently from your passport. It has to match letter for letter, including both surnames.
- Leaving the foreign address blank. Even if you have lived here for years, that field gets filled.
2. Your tax return
The W-7 almost never travels alone: it is stapled to that year’s return. This is the part that confuses everyone, because it looks like a loop — you cannot file without an ITIN, but you cannot get an ITIN without filing. The way out is to send both together, leaving the tax ID space blank.
There are exceptions —applying only to open a bank account, for instance— and they are listed in the official form instructions.
3. Proof of identity
The IRS accepts thirteen documents, but in practice it comes down to two routes:
- A valid passport, on its own. It is the only document that proves identity and nationality at the same time.
- Two documents from the list if you have no passport: consular ID, foreign driver’s license, birth certificate, school records for minors.
Never mail your original documents. There are two alternatives and both are free or nearly free.
Where to file without handing over your passport
Certified Acceptance Agent (CAA). They verify your passport, hand it straight back and send the certified copy. They charge, but usually $50 to $150, not $500.
IRS Taxpayer Assistance Center (TAC). Free, by appointment. The city has offices in Manhattan, Brooklyn and Queens. Appointments disappear fast during tax season: book in January if you plan to file in April.
How long it takes
Seven to eleven weeks outside of tax season. Between January and April it can stretch to fourteen or more. The letter with your number arrives by mail to the address on your W-7, so if you move mid-process, tell the IRS.
Every five years
An ITIN expires if you do not use it for three consecutive years. They also expire in batches based on the middle digits. Renewing means the same W-7 with the renewal box ticked, and you do not need to attach a return.
Mistakes that cost months
- Sending uncertified photocopies. Rejected every time.
- Using an address where you will not be in three months.
- Applying in April. If you can, do it between June and December.
- Paying someone who promises an “ITIN in a week.” It does not exist.
