The IRS assigns Individual Taxpayer Identification Number (ITIN) to individuals who are needed to have U.S taxpayer identification number but who do not have and are not eligible to obtain, a Social Security number (SSN). Your ITIN helps you comply with the U.S. tax laws and accounts for tax returns and payments.
Although this number is very important, it is very likely to get lost. So, here’s what you need to do when your ITIN gets lost:
  • If you lose your ITIN, you DO NOT HAVE TO submit another W-7 ITIN Application Form to IRS. So, you are not asked to apply for a new one. As soon as you are identified and verified, you will receive a copy of your number via mailing by the IRS.
The first thing to do is contacting the IRS. Then you will be asked to answer some series of questions that are required to verify your identity.   You can call the IRS toll-free at 1-800-829-1040. If you are outside the U.S you can call 1-267-941-1000.

IMPORTANT NOTE:

It is possible for you to recover your ITIN by calling the IRS. However, you are likely to spend plenty of time on the line for the recovery process. Please keep in mind that it is always logical to store your number in a safe place so that you can always have access whenever you need it. This safe place might be your phone or a family member.