Do I need to file extension if I am applying for ITIN?

[awonaph]

I just mailed in the tax return along with the ITIN application, since it said that I needed to include a completed and signed tax return to apply for ITIN.

Do I need to wait and get the ITIN number and file the tax return once again, even if I mailed in the tax return with the ITIN? Would the tax return that I submit along with the ITIN application get processed?

[DawnC0]

You do not need to do an extension.  As long as your return was included with your ITIN application, yes, it will be processed along with your application.  Once the ITIN is assigned, they will forward your return for processing and send you a letter with the ITIN.  Processing the tax return will take an additional 4-8 weeks.  

If you qualify for an ITIN and your application is complete, you will receive a letter from the IRS assigning your tax identification number usually within six weeks. If you have not received your ITIN or other correspondence six weeks after applying, call the IRS toll-free number at 1-800-829-1040 to request the status of your application if you are in the United States. If you are outside the United States, call 267-941-1000 (not a toll-free number).