1099-Misc from Property Manager includes 3 units I own, but one unit is partially owned by another person

Yes, there is a way to split the income between the three properties.  If the information on the 1099-MISC is entered into your tax return on Schedule E, you do not need to enter the 1099-MISC form into your tax return. You can divide the rental income between the three properties on Schedule E that are short-term rentals.

To report the income for the property that was 50% owned by your brother-in-law, you will need to file as a nominee.

Nominee Actions/Returns:

Generally, if you receive a Form 1099 for amounts that actually belong to another person or entity, you are considered a nominee recipient. You must file a Form 1099-MISC with the IRS (the same type of Form 1099-MISC you received).  You must also furnish a Form 1099-MISC to your brother-in-law. 

File the new Form 109-MISC9 with Form 1096 (this is a transmittal for the 1099) by mailing to the Internal Revenue Service Center for your area. (Provided on the Form 1096)

• On each new Form 1099, list yourself or the original Payee as the payer and the other owner, as the recipient. On Form 1096, list yourself or the original Payee as the nominee filer, not the original payer.  The nominee is responsible for filing the subsequent Forms 1099 to show the amount allocable to each owner.

The forms filed with the IRS should be the red copy so if you don't have a color printer, go to the IRS website and order the forms here: 

• Form 1096-Transmittal 
• Form 1099-MISC

Split the amount as needed and enter only the necessary portions on the appropriate returns.