What is an ITIN used for and who has one?
IRS issues ITINs to help individuals comply with the U.S. tax laws, and to provide a means to efficiently process and account for tax returns. They are issued regardless of immigration status.
Source: IRS (https://www.irs.gov/tin/itin/individual-taxpayer-identification-number-itin#what)
You can also use it to: open a bank account, get a credit card, obtain a loan / mortgage.
Source: American Immigration Council (https://www.americanimmigrationcouncil.org/research/facts-about-individual-taxpayer-identification-number-itin)
Taxpayers who file their tax return with an ITIN include undocumented immigrants and their dependents as well as some people who are lawfully present in the U.S., such as certain survivors of domestic violence, Cuban and Haitian entrants, and certain spouses and children of individuals with employment visas. As of December 31, 2022, the IRS had issued 26 million ITINs since the program’s inception, and there were more than 5.8 million active ITINs.
Source: National Immigration Law Center (https://www.nilc.org/resources/itinfaq)