The US Tax Code and treasury regulations control and define a tax deferred exchange and require that the property involved be of "Like Kind" and income producing. This second property must be of equal or greater value.
All of the sales proceeds and cash must be re-invested in this new comparable property, and the transaction must be handled by a non-involved but qualified third party, known as a "Qualified Intermediary".
If the first property is indebted, the new purchase must be subject to debt at equal or greater level as well. If not, additional cash must be entered to equal the difference.
