The unique characteristic of an Illinois last will & testament that distinguishes it from other estate planning and asset transfer documents is that only a last will and testament can make a complete transfer of an entire property interest of the owner, effective at death. If the owner of property attempts to make a disposition effective only at death and not before, other than by use of a last will and testament, such a disposition will be invalid. Certain kinds of property transfers under other transfer documents are effective at death, but they do not transfer the entire interest in the asset at death – instead, some interest in the asset, however contingent or revocable (for example, beneficiary designations, pay on death designations, etc.), is transferred prior to death.  Property that is disposed of in the latter case is called “non-probate” property (as contrasted with “probate property” which passes only under a will).  It is possible to dispose of all estate assets by a last will and testament (sometimes referred to as a simple will), or by creating non-probate assets, or any combination of probate and non-probate dispositions.

A last will and testament may also contain trust provisions (called a “testamentary trust,” which is different from a “living trust”).  A last will and testament is a revocable document that takes effect only upon a persons death. This means an individual can change the provision of the last will and testament at any time before his or her death.