I just couldn't find an out in the conversation because every time I said no thank you, he just kept pushing. Did I also mention I have a no solicitation sign right next to the doorbell? If you have a No Solicitation or a No Trespassing sign, they cannot knock or ring the bell. So I guess the bottom line is: if you have a No Soliciting or No Trespassing sign, your house should technically be untouchable. Five Cities with the Highest Sales Tax Rates in Colorado In these five Colorado towns, you will be paying at least 10 percent or more for sales tax when you purchase something.