Joint Sponsor is Self Employed-questions

[planbee]

Hello, I have nearly completed all the paperwork for adjustment of status through marriage to usc but am waiting on my husband's father to finish paperwork for joint sponsor/I-864. I am needing his tax information, but because he is a business owner and files k-1 taxes, he says that his tax stuff for this year could take a while to come through. I am wondering if I should wait for his tax filing for this year to be ready, or whether I can just use his tax information for the last years and then when he gets the tax information for this year I bring that to interview whenever that happens.

hope this makes sense.