Posting "no trespassing signs" is a way to keep you and your property safe. The police department in Granite City, Illinois, recommends that residents post "no trespassing signs" to deter crime. In Wheeling, Illinois, door-to-door solicitors and salesmen are not allowed to knock on the doors of any homes that have a "no trespassing" sign. Find out if there are any regulations specific to your town or county before posting "no trespassing" signs.
Post your no-trespassing sign near the entrance of your property. If you live on a farm, or another property where there is a large space between you and the next house, post signs behind your house as well. The sign(s) should be noticeable with writing large enough to be read. Someone can be charged with trespassing if he has been given notice that he is not allowed to enter your property; this notice can be provided with an obvious sign
Contact your municipal government office to find out if there are any regulations regarding no trespassing signs. For example, in Flossmoor, Illinois, residents must post their signs at least 5 feet back from the beginning of their property line and multiple signs must be posted at least 100 feet apart. Additionally, signs can be no larger than 2 feet square and posted no higher than 4 feet off the ground.
Post a no trespassing-no parking sign if you plan on towing, or hiring a company to tow vehicles, that park on your private property. In Illinois, it is illegal to tow trespassing cars if no sign is posted. Include a message on the sign that indicates the prohibition of parking and trespassing and that warns of the consequences of being towed, including the towing fees; provide the name, address and telephone number of the towing company, if applicable. Use a sign at least 24 inches long and 36 inches wide and post it between 4 and 8 feet off the ground. Post the sign in a conspicuous spot and use artificial lighting or reflective paint, so it shows up at night.