OTTAWA – Certified letters will be issued to LaSalle County residents if they don’t pay their taxes by Friday, according to the LaSalle County Treasurer’s Office. In a letter from LaSalle County Treasurer James Spelich, real estate taxes must be paid on or before Friday at 8 a.m. After Friday, the treasurer’s office will only accept cashier’s check, money order or cash. A 10 dollar certified letter fee is added to any payments received in the office after Friday. October 12th is the official last day to pay before your name is published.