The amount of time it takes to probate an estate will depend on a number of factors, including the size and complexity of the estate, the abilities and dedication of the Executor/PR, and whether or not any challenges are filed against the estate. Furthermore, state law determines how long creditors have to file claims against an estate. The probate process must remain open at least that long. In Illinois, a Probate case will generally last at least six months because of the claims publication requirement under the Illinois Probate Act. It can easily take much longer though to get through the probate process.