When you repossess your property after making an installment sale, you must figure the following amounts.
1.Your gain (or loss) on the repossession.
2.Your basis in the repossessed property.
Link to IRS guide and worksheets.
Repossession and Mandatory rules.
http://www.irs.gov/publications/p537/ar02.html#en_US_2016_publink1000221751
