How do real estate tax prorations work?

A good Buyer’s real estate attorney should review the Contract during the Attorney Review period to make sure the real estate tax prorations are appropriately calculated in the contract. Property taxes are paid in arrears in the state of Illinois. For example, real estate taxes payable for 2018 are paid in installments in 2019. Therefore, if a property closes in 2019, the Seller will give Buyer a credit at closing for the 2018 real estate taxes that are payable in 2019. If the 2018 real estate tax bill has already arrived, then the Seller will give Buyer a credit at closing for the actual amount disclosed on said real estate tax bill. If the 2018 real estate tax bill has not arrived as of the time of closing, Seller is required to give Buyer a credit at closing for a set percentage of the last ascertainable real estate tax bill to cover any increase in taxes there might be in the 2018 real estate tax bill. Typically in Cook County, this percentage is 110% of the last ascertainable real estate tax bill. Typically, in Lake and other collar counties, this percentage is 105% of the last ascertainable real estate tax bill. The Seller will also give Buyer a credit for either 110% or 105% of the last ascertainable real estate tax bill for the number of days in 2019 that Seller owned the property. Typically, the prorations are final at closing and Buyer bears the responsibility of paying the real estate taxes when the real estate tax bills arrive post-closing.