"Flat rate" may seem to refer to the flat-on-your-back dead faint you experience when you read your monthly bills. Your apparent bargain phone plan skyrockets from $30 to $50, thanks to hidden fees. The late fees and other service charges you pay on your credit cards add about $13 billion a year to the banking industry’s bottom line. You may live in an era when it costs money just to get money at an ATM, but you don’t have to take it sitting down. On the following pages are strategies to help you avoid some of the most common ancillary fees associated with everything from credit cards to rental cars. It’s money-saving advice, with no hidden charges.

CREDIT CARDS

Late-Payment Fee

Why You’re Being Charged: Your credit-card company doesn’t care that the check is in the mail. If it’s not at the payment center by the due date — and usually by a certain time on that date (check the fine print of your billing statement) — you’re going to get slapped with a fee.
The Cost: $29 to $39. Also, nearly half of all major credit-card issuers now have a “universal default” feature, which means that late payments on one card can lead to a higher interest rate not only on that card but also on cards you have through other banks.
How to Avoid It:

Mail your payment (or pay online) as soon as your bill arrives, or at least five working days before the deadline. You can also ask your credit-card company to set up your own easy-to-remember deadline (the first of the month, for example). Or sign up for an automatic-payment plan.

If you are late with a payment, call the company and ask if it will remove the charge as a courtesy. If you have a good payment record, the company may let you slide once.

Over-The-Limit Fee

Why You’re Being Charged: No buzzer sounded when you exceeded your credit limit; the cashier didn’t even ask you to pay with another card. “People think their bank will cut them off, but it won’t,” says Linda Sherry of the advocacy group Consumer Action.
The Cost: $29 to $39. And you’ll keep paying the fee, plus interest, every month your balance remains over your limit.
How to Avoid It: Know your balance. A 2002 study by the nonprofit consumer-education organization Myvesta found that 24 percent of people don’t even look over their credit-card bills each month. Bad move. If you’re between statements and contemplating a big purchase, first check your balance either online or with a toll-free call to the card company.