When you infer that "we co-owned a rental property" is "we" two specifically named individuals that are not related or married to each other? Of is "we" in reference to a partnership that "we" were members of, which filed it's own 1056 partnership return each year?
"I am the only person on the loan."
Then as far as that lender is concerned, you are the only one legally liable for paying off that loan with proceeds from the sale. I expect the closing agent took care of that at the sale.
"Both of us paid for the mortgage. "
That's fine. The one on the loan can claim the interest that they actually paid and can prove they paid, since they do have a vested interest in the property. But this is moot since the property was sold.
"The property gain is 80k. I took 5k and he took 75k. "
Not an issue with a 1065 Partnership return, since distributions shown on the K-1 have nothing to do with percentage of ownership.
"I took a lost as i invested more than 5k. "
Don't count on that, since at the time of the sale you have to recapture all prior depreciation and pay taxes on it.
"Am i supposed to pay for the property gain?"
What does your partnership agreement legally obligate you to do? If there was a gain on the sale, there will be tax on that gain. The IRS doesn't care who pays it. But I guarantee you it will be paid one way or the other, sooner or later.
"Will there be a 1099 form stated i only received 5k?"
That's up to the bank or agent that handled the sale. Generally when investment property is sold and a check in any amount is handed to the seller(s) at the closing, the agent will issue a 1099-S showing those net proceeds paid to the seller.
