Your spouse's income is needed for a number of reasons, like eligibility for certain credits or deductions, handling property you own together, etc…
If you can't estimate what your spouse's income is, then enter 17350 as the net income. Or, if you say your spouse has zero income, don't claim the spousal amount. Either way, remember to change it when you have the correct number.
This is why we recommend that spouses prepare their returns together - the software will automatically enter and adjust this number.
