Legal / Tax question regarding "partnership"

[Rudy Estrada]

Hello everyone, I am a new real estate investor. I am currently on contract to purchase a condo in College Station, TX. My sister and I will purchase the condo on both our names and have agreed to be "partners" in the deal. I also have established a TX LLC (as a partnership with a different person); however, we were not able to purchase the property under the LLC due to the lack of financial history. My question is, do we have to file paperwork to register the partnership, or can we just document on a partnership agreement and file our respective share on our taxes?

Thank you so much in advance for your input.