Flipped Property with a partner -can one partner claim Schedule D and other Schedule C?

[speedway121]

I had a partner who does flips very regularly. He is in the real estate business , he has many rentals and also does a lot of flips annually. 

I am unsure if he filed the specific flip we worked together on on his Schedule D or Schedule C - and I am questioning if we should both match - if he claimed Schedule C I should prob do the same? 

If he claimed schedule D shouldnt I do the same? 

He wont tell me what he did ( I asked) and he does not want divulge the info. 

[ColeenD3]

While he may have filed Schedule C in the past when doing it alone, the two of you have now formed a Partnership. You must file Form 1065.

A partnership is the relationship between two or more people to do trade or business. Each person contributes money, property, labor or skill, and shares in the profits and losses of the business. An unincorporated organization with two or more members is generally classified as a partnership for federal tax purposes if its members carry on a trade, business, financial operation, or venture and divide its profits.

PUB 541

[Mike9241]

while Turbotax business can do a 1065, it may be best to use a tax pro to do the first year's return.   there can be many issues.  in addition, the return was due 3/15/2021. the penalty for late filing is about $200 per month per partner. while the IRS usually waives first-time late filing penalties it does require a written request.