Do I owe taxes on the money I received for a buyout of a property I once owned with my former fiancee?

[cageymom]

In order for me to relinquish my interest in the property we settled on amount that I would be paid to compensate me for my interest in that property. I received a lump sum of 30k and no longer am on the title, deed or mortgage.

[ThomasM125]

That would not normally be taxable. The only way it would be taxable is if the property was sold at a gain, in which case you  may have to pay tax on the gain.

[Opus 17]

Because you were not married, this is not a tax-free transfer of property related to a divorce.  It might be taxable if you have a capital gain.  That is, if you received more than you originally invested.

That may be very hard to show one way or the other.  Unfortunately, if you happen to be audited, the IRS does not have to prove you had a gain, you have to prove you did not have a gain.  

Let me make up an example to show you how I would think about it.

Suppose you bought the house together for $100,000, and you both put down $10,000 and both paid half the mortgage.  When you split up, the house was appraised for $150,000 and the remaining mortgage balance was $75,000.  Your equity was $37,500 and you agreed to accept $30,000.  Because you originally invested $10,000, and you are responsible for half the amount of that the mortgage was reduced ($2500), then you invest $12,500 in the house and received $30,000 so you have a taxable gain of $17,500.  If you owned the home more than 1 year, that's a long term capital gain.

Your numbers are surely different, and you may or may not have a gain.  You also might have paid more or less than half the downpayment and expenses.  But that would be my thought process on how to calculate your gain, if you had one.