There is not a straightforward and simple way to do
that.
Creating a Married Filing Separately return for one of you
in an online account that you will not file would give an estimate of how the
refund might be split. However, if
certain credits are involved, then the answer will not be an accurate one since
there are some restrictions with claiming credits when using Married Filing
Separately.
If you are using the CD/downloaded version of TurboTax,
there is a “what-if” worksheet that can be used to compare Married Filing Joint
and Married Filing Separately, but again the answers would not be exactly what
you are looking for.
One thing that you may consider doing is to file an Injured
Spouse form with your return. The
purpose of this form is to protect your share of the refund on a joint return
when one spouse has a previous debt that would seize a tax refund. It will take longer for the IRS to process
the tax return, but only the refund attributed to the person who owes the debt
would be used to pay the debt. The
Injured Spouse form itself will allocate the income and deduction items between
the two parties, but it does not fully show the division of the refund because
certain credits must be allocated by the IRS when they process the return.
See the information below for more details about the Injured
Spouse form as well as the “what-if” worksheet.
https://ttlc.intuit.com/replies/3326788
https://ttlc.intuit.com/replies/4775330
