Many consumers assume if they opt out of credit card offers, there will be fewer credit inquiries on their credit reports, says John Ulzheimer, president of consumer education at SmartCredit.com. However, those inquiries are considered "soft" inquiries and don't affect your credit score, Ulzheimer says. You can keep the offers coming if you'd like, but doing so won't help you build better credit.

If you want to opt out of offers to reduce your junk mail, call toll free (888) 5-OPT-OUT / (888) 567-8688), or visit OptOutPrescreen.com to remove your name from the credit reporting agency lists for unsolicited credit and insurance offers. That will remove your name for five years.

To keep your name off the list, mail in the permanent opt-out election form available on the website. Consumers can also opt in on the website if they've already opted out.