A credit card is the safest way to pay for items online. With credit cards, you'll get security protection from your card's issuer. Visa, MasterCard and American Express all have a zero liability policy. If you notify the bank of unauthorized transactions, you pay nothing.

Also, with credit cards, you can assign password challenges for purchases. When you buy something, you're prompted for a password. This offers another layer of protection. MasterCard offers SecureCode and Visa offers Verified by Visa.

These programs only work at participating sites. To learn more, visit www.MasterCard .com and www.Visa.com.

As with credit cards, many debit cards have fraud protections. You can dispute charges to your account. But with a debit card, your money is tied up while you dispute charges.

Some online stores provide regular customers with promotional codes. You enter these when you check out. And they'll save you money.

With promo codes, you may get free shipping or a price reduction. Stores may have multiple codes, so pick the best one.

If you're not a regular customer, you can still find promo codes. Coupon Cabin (www.couponcabin.com), RetailMeNot (www.retailmenot.com), Current Codes (www.currentcodes.com) and Naughty Codes (www.naughtycodes.com) have them. Other sites also offer them.

Many sites aggregate prices from other sites. Enter a product name and sort through the results. You can sort the results by the lowest price or highest-rated store. Most allow you to enter your ZIP code so shipping is included.

www.PriceGrabber.com, www.Shopping.com, www.PriceSCAN.com and Froogle (www.froogle.google .com) all offer price-comparison searches.

When you buy online, there's the chance that your items won't arrive. Protect yourself by sticking with trusted merchants.

An established site such as www.Amazon.com is less likely to give you problems. But if you use a price-comparison site, smaller sites may have better prices. So you may opt to give them your business.

Before you do, though, do some research. Read reviews left by other shoppers. And look at their ratings.

When you buy online, you must provide an e-mail address. The store will contact you with tracking information and order confirmations. You could also get spam.

So create a new e-mail address via a free provider. Hotmail (www.hotmail.com), Yahoo (www.yahoo.com) and Gmail (www.gmail.com) all offer free accounts. Use this account when registering and buying at online stores. When your purchases are complete, you won't need to worry about more e-mail from the merchant.

E-mail Kim Komando at gnstech@gns.gannett.com.