Mail: USPS First class mail with tracking -complementary. Express mail: paid by the taxpayer.
To get started with ITIN services:
Create a client portal account (choose ITIN/CAA during registration)
Fill out the ITIN pre-qualification questionnaire.
After reviewing the answers, you will receive an engagement letter if you qualify to get the ITIN. If more information is needed, your CAA will reach out.
Read more about ITINs