No SSN or ITIN... what is default SSN / ITIN

There is no such thing ... all people listed on a return must have one or the other.

Are you going to file for an ITIN with this return ?    If so you can use 999 - 99 - 999 as a place filler so you can print the return to mail with the W-7.

Enter "Applied For" in the social security number slot under the Personal Info tab, if that doesn't allow you to proceed to file by mail try the SSNs shown below. If you use numbers, be sure to white them out after print before mailing your return.

What is Form W-7: Application for IRS Individual Taxpayer Identification Number? Prepare a Form W7, for each person who needs an ITIN, then include it with the required documentation with your return.  File the return to this address.

• Internal Revenue Service
• ITIN Operation
• PO Box 149342
• Austin TX 78714-9342

For more information you can use this link:     IRS - W7 Instructions

FYI, this applies to the current tax year, 2016. Follow these steps to prepare your return for mailing.

1. Complete IRS Form W-7.
2. Complete your federal and state tax returns using the number 999-88-9999 in place of a Social Security Number.
3. Print the tax returns and cross off the 999-88-9999 from the SSN field. Do not attempt to e-file your return.
4. Write "Applying for ITIN; Application attached" next to the SSN field.
5. Mail the signed federal return, the completed Form W-7, and all documentation required by the Form W-7 (Alternatively, you may choose to take all this information in-person to a local IRS office for processing.)  
6. If you need to file a state tax return: Mail the signed state return and a copy of Form W-7 to your state's regular filing address.