There's no official IRS "express" ITIN service — but applications that are complete and correctly documented the first time move noticeably faster than ones the IRS has to send back for corrections.
This guide covers the single biggest lever for speed (getting it right the first time), when to expect your number, and when a Certifying Acceptance Agent is worth using.
What actually determines how fast you get your ITIN
Processing time depends on completeness, not on how urgently you need it. A complete Form W-7 application with the right reason code and valid ID documents is typically processed in about seven weeks.
An application with an error — wrong reason code, expired document, missing tax return — gets rejected and restarts the clock from scratch, often adding months.
The fastest route in practice: a Certifying Acceptance Agent
A CAA reviews your documents before submission, catching errors the IRS would otherwise reject.
You keep your original passport — no risk of it being lost in the mail or held for months at IRS ITIN Operations.
If you also need an ITIN as part of a bigger application (like Form W-7 for a dependent), a CAA can prepare the whole package at once.
Timing around the tax season
January through April is the IRS's busiest period for ITIN processing, since most applications arrive attached to a tax return. If your filing deadline isn't fixed to that window, applying in the off-season (May–December) can mean a faster turnaround.