What you need to know about how property taxes are handled when you are buying or selling real estate:
In Colorado, the property taxes are paid in arrears, which means that the 2011 property taxes are due in 2012. Taxes can be paid in either 2 half-payments, due around February 28th and June 15th, or in full on April 30th. (Confirm the exact dates, which change slightly from year to year.)
If you have a mortgage, the mortgage company will most likely collect a small amount as part of your mortgage payment each month and place it into an escrow account, and then they will pay the taxes when they are due from that account. (They typically do the same for homeowners insurance.)
When you are purchasing a house, you will receive a credit from the seller for any taxes that are not yet due, and then you will be responsible for paying them the next year when they are due. For example, if you close on your new house on June 30th, 2012, you will receive a credit on the settlement statements at the closing for the pro-rated taxes from January 1, 2012 – June 30, 2012. Then, in 2013, when those 2012 taxes are due, you will be responsible for paying the entire 2012 property tax bill.
When you are selling a home, you will give the credit to the buyer at closing. This is considered a final settlement, so regardless of whether the taxes increase or decrease, neither party will be able to come back and claim that they are owed money.