Spring brings not only budding plants and warmer weather. It also brings out vendors selling goods and services door-to-door.

Although federal law requires a three-day “cooling off” period in which you can change your mind about any item sold door-to-door, the Better Business Bureau suggests these tips to avoid having to invoke the rule:

• Harsh as it may seem, simply ignore unfamiliar salespeople. Let them knock or ring your bell. Peep out. If you don’t know them, don’t waste your time and theirs by opening the door.
• If you do open the door, don’t invite them in. Salespeople are trained to draw you into a conversation that can easily lead you into a sales pitch for something you don’t want or need.
• If a product sounds somewhat appealing, ask for a brochure and say you want to look it over and get back to them. Don’t let someone push you for an on-the-spot sale. If a product or service is worth it, it will stand up to a deliberate examination on your part and on your own time.
• Ask all salespeople to show you proof that they are licensed and insured. They confronted you by knocking on your door. You have the right to ask questions and ask for proof.
• Don’t settle for verbal assurance. Get everything in writing. And never sign a contract with any blank spaces or blank pages.
• Don’t pay in advance. A general rule is one-third payment up front, one-third halfway through the job, and one-third on completion.
• Someone offering to use “leftover material from another nearby job” almost always is conning you. Ask for contact information from the customer on that job so you can inquire. If the seller won’t answer, the entire story may be a ruse.