The simplest way is to report it only on the return whose SS# was listed on the K-1 form. If you want to split it up and enter each person's portion on their return then you chance the IRS sending a CP2000 notice in a couple of years for the missing income. So if you can agree you can do it that way ... I would complete the entire return without the K-1 form and note the refund or balance due then add the K-1 and again note the refund or bal due.... then figure out how you want to handle the 1/2 of the difference between the 2 of you if you keep everything separate or just let it be. For non married taxpayers, if you want to invest in something and want the income listed in both of your SS#s then you need to set up a partnership that would recieve the one K-1 form then split it into 2 K-1 forms.
