The client is in a 25% / 75% partnership with a co-worker and they bought their first house to flip in 2022.

House sold in 2023. I understand IRS rules regarding house flipping (cap costs increase basis, non cap expenses taken in year incurred, etc),  but I just found out the LLC they formed wasn't valid until 2023. Is there a way to file the 2022 loss on a Sch C? If so, how do you show the distribution of loss?

Thanks!