There's a lot of information out there about credit cards and how to use them. Yet some well-intentioned advice can actually lead you in the wrong direction.

Here are six myths that, at first glance, seem to reflect common sense. In reality, though, these half-truths can end up costing you.

Myth No. 1: Never use emergency funds to pay off credit card debt.

Reality: If you're earning 4 per cent a year on your emergency savings while paying 20 per cent annually in credit card interest, that's a yearly loss of $160 for every $1,000 of outstanding card debt.

According to "Why Smart People Make Big Money Mistakes and how to Correct Them" by Gary Belsky and Thomas Bilovich, it makes more sense to pay off high-interest credit card debt with emergency savings and then consider the freed-up credit as emergency money. You'll save on interest charges -- plus, reducing your balance makes it more likely that the card issuer will raise your credit limit when you really need the enhanced purchasing power.

Tip: Before having to face an emergency, make paying down high-interest debt your priority.

Myth No. 2: Lines of credit resolve credit card debt.

Reality: Consumers who refinance their high-interest credit card balances with a low-cost line of credit often don't change their out-of-control shopping habits.

"Many people who go back to spending more then run up both credit card balances and the line of credit," says chartered accountant and author David Trahair. "Those consumers end up in a worse position than if they had simply paid off their lower-rate line of credit to begin with."

Tip: Stay focused on reducing debt balances, and don't be distracted by enticingly low interest rates.

Myth No. 3: Buying online with credit cards is too risky.

Reality: Credit card companies provide zero-liability policies and other programs that help safeguard web shoppers.

MasterCard offers a free benefit called SecureCode, enabling registered cardholders to assign a private code that is then required to buy from almost 600,000 participating online retailers. Verified by Visa is a similar service that enforces password protection for web purchases. In addition, the Visa E-Promise program lets cardholders direct their card issuers to cancel or reverse charges when orders aren't received or when delivered items don't match what was advertised.

Tip: Immediately notify the credit card company about any suspicious items on your statement.

Myth No. 4: Cardholders should avoid charging big-ticket items.

Reality: Provided that you budget for major purchases, you can save money by taking advantage of rewards credit cards with built-in freebies such as extended warranties and purchase security insurance.

Even for unexpected expenditures, credit cards with the free price protection benefit can be a superior option to paying with cash. Price protection ensures that if you find a lower price within 60 days, you can be reimbursed for the difference. If your refrigerator breaks down and you need an immediate replacement, the price protection perk can result in major savings.

Tip: Pay outstanding balances by the statement due date. Otherwise, interest costs will negate card benefits.

Myth No. 5: Recurring charges are riskier when paid by credit card.

Reality: By automatically deducting repeat expenses via your credit card, you add an extra layer of protection between you and the biller. In fact, assuming that you meet all requirements in the sales contract, your issuer can help you resolve billing disputes.

Tip: Keep all your paperwork organized. Credit card statements can serve as a historical audit trail for contesting charges.

Myth No. 6: Good credit scores guarantee credit card maximums.

Reality: Cardholder agreements give credit card companies the right to decrease your credit maximum at any time -- and without advance notice.

Money maven Gail Vaz-Oxlade is an outspoken critic of Canada's credit-scoring system. Vaz-Oxlade describes on her blog how credit limit cuts can push account holders' debt-to-maximum ratios to dangerous levels, which, in turn, can cause cardholders' scores to drop -- and provide credit card companies with justifications for interest rate hikes.

Tip: Try not to exceed 30 per cent of your account maximum.

See related: 7 myths about joint credit cards; Store credit cards: The good, the bad and the ugly