In another thread, we had a very robust discussion on where a proprietary trader should take excess expenses that were not reflected on the K-1 that the proprietary trader received. After much debate, I concurred with several other posters that the correct answer is that such expenses are listed on Schedule E, line 28, column (h) as a separate line entry--not aggregated with the other expenses from the K-1.
So if I understand your facts correctly, you have exactly that situation. You have a business expense that was not listed on the K-1 you received. If that is correct, the answer on where to list it is as listed above.
A significant and related question though is whether such expenses need to be capitalized as opposed to deducted as a current expense. If these expenses need to be capitalized, you've got a much different situation. Generally, capital expenses must be deducted by means of depreciation or amortization. I don't have time at the moment to research whether the proprietary software development costs are a capital item as opposed to a deductible expense, but some of the other participants on this forum may have looked at that issue.
So if I understand your facts correctly, you have exactly that situation. You have a business expense that was not listed on the K-1 you received. If that is correct, the answer on where to list it is as listed above.
A significant and related question though is whether such expenses need to be capitalized as opposed to deducted as a current expense. If these expenses need to be capitalized, you've got a much different situation. Generally, capital expenses must be deducted by means of depreciation or amortization. I don't have time at the moment to research whether the proprietary software development costs are a capital item as opposed to a deductible expense, but some of the other participants on this forum may have looked at that issue.