VICENZA, Italy -- All individuals listed on a federal United States tax return must have an identification number.

While United States citizens and permanent residents (also called "green card holders") may use a Social Security number, non-United States persons must apply for and be issued an Individual Taxpayer Identification Number (ITIN).

If this is the first year you will require an ITIN, you may apply for one when the tax return is filed this tax season. However, those who have been issued an ITIN in the past must be sure to check the expiration date. ITINs that contain middle digits of 70, 71, 72, or 80 (e.g. 9NN-70-NNNN), or that have not been used on a tax return in one of the past three tax years, expired on Dec. 31, 2017, and must be renewed.

Taxpayers may renew the ITIN immediately and do not have to wait for a notice from the IRS to do so. Failing to renew the ITIN as soon as possible could delay processing of any entitled refund.

To renew the ITIN, submit a completed Form W-7 with all required supporting documentation. Just like when the ITIN was first issued, supporting documentation must be certified by the issuing agency. Stop by the Vicenza Tax Center in Building 166 on Caserma Ederle, with any questions about the process.