If you have already applied for an ITIN, wait to file your tax return until you receive it. File an extension if you have to wait past April 18.
If you need to apply for an ITIN, you will mail the W-7 ITIN application and your completed tax return to the IRS office that handles W-7 applications (see the instructions) and not the IRS office that would normally handle your tax return. Turbotax won't take all 9s but 999-88-9999 should work. Then before mailing your return, use some white-out to cover the fake number on the printed copy.
