An ITIN, or Individual Taxpayer Identification Number, is a tax processing number issued by the Internal Revenue Service (IRS) to individuals who are required to have a U.S. taxpayer identification number but are not eligible for a Social Security Number (SSN).

• Individuals who are not eligible for an SSN but have a tax filing requirement in the U.S. need an ITIN. This includes non-resident aliens, dependents of U.S. citizens or residents, and individuals who earn income in the U.S. but are not authorized to work.

Processing times can vary, but it usually takes about 7 to 11 weeks for the IRS to process and issue an ITIN. This timeframe may be shorter or longer depending on the time of year and the volume of applications.

Yes, ITINs can expire. As of 2013, ITINs that have not been used on a federal tax return at least once in the past three consecutive tax years will expire. You can renew your ITIN by submitting a new W-7 form along with your tax return when needed.

You will typically need to provide original or certified copies of documents that establish your identity and foreign status. This may include a valid passport, visa, or other government-issued identification documents.