American Express offers a line-up of travel rewards cards designed specifically for high spenders who pay off their balance in full each month. Although they seem to be credit cards, they really aren’t. They are charge cards, which are something quite different because rather than having the option to make partial payments and carry a balance, charge cards must be paid off in full.

Charge cards don’t charge interest, but late payers face a stiff penalty of 30 percent of the balance.

Another important distinction is that charge cards, unlike credit cards, don’t come with a pre-set spending limit. That doesn’t mean you’ll get unlimited spending power, but it does offer a way for big spenders to put all their expenses on one card to help rack up mega rewards points.

American Express’ suite of Charge Cards

Amex’s suite of charge cards includes the popular American Express Gold Rewards card, American Express Platinum card and all three tiers of AeroplanPlus cards. They also carry a full line of charge cards for business owners. (Amex also has some credit cards, which allow you to carry a balance).

Related: American Express Air Miles Platinum – My latest travel points hack

Charge cards are aimed at two types of customers:

• The more affluent customer who has no real need for credit, but who spends a lot and wants to earn big rewards.

• The other type of customer is one who’s averse to debt, yet financially responsible.

A charge card combines the discipline of a debit card with the benefits of a rewards card. An Amex spokesperson said that customers who consistently miss payments will be moved to a more traditional credit card.

Since they don’t profit much from interest rates, American Express makes money capturing merchant fees from retailers each time you swipe your card. Their line-up of charge cards also comes with some fairly hefty annual fees — $150 for the Gold Rewards card, $499 for the AeroplanPlus Platinum card and $699 for the Platinum card.

While Visa, through its controversial smallenfreuden campaign, wants customers to put small, everyday transactions on credit to help increase card spending, American Express also hopes to capture a larger percentage of consumer spending to gain on its rivals.

To do so, they’ve offered some of the richest and most robust rewards programs in order to lure affluent spenders.

Charge cards are an enigma because, while they’re designed for people who have the discipline to spend less than they can afford, the accompanying rewards programs are geared toward wealthy customers with a taste for travel and experiences that are beyond decadent.

But the trouble for American Express has always been that its cards aren’t as widely accepted by merchants across the country. This can turn-off potential big-spending customers, or force them to carry another credit card, which leaves American Express as the second or third option in a customer’s wallet.

Related: Which bank offers the best rewards cards line-up?

A charge card might be a good fit for those who travel frequently or rack up a lot of expenses for business. You’ll benefit from a much higher spending limit than a traditional card. This way you can charge more of your expenses to your card and take advantage of a generous rewards program, making the annual fee a bit easier to swallow.

Just take care to pay your bill in full and on time, and don’t get caught up trying to obtain rewards that require an obscene amount of spending.

Last year I managed to nearly double my credit card rewards (to more than $1,500) by signing up for a few select promotions that paid juicy bonus points.

I wasn’t sure I’d be able to find such good deals again this year because several banks and credit card providers were discontinuing or devaluing their premier rewards cards. But I was wrong.

Today I signed up for the American Express Air Miles Platinum credit card. The offer is a good one. Earn 2,000 Air Miles when you charge $500 to your card within the first three months. The annual fee – only $65 to begin with – is waived in the first year.

American Express Air Miles Platinum Credit Card

I prefer Air Miles Cash to Air Miles Dream rewards because I like the instant gratification of the eVoucher program. 95 Air Miles gets you $10 off at grocery stores, gas stations, or the movies, to name a few. That means 2,000 Air Miles can get me more than $210 worth of stuff that I would normally buy anyway.

Related: Air Miles e-Voucher breathes new life into rewards program

Use the American Express Air Miles Platinum card at Air Miles sponsors and at other eligible grocery stores, gas stations, and drugstores in Canada and earn 1 Air Miles for every $10 spent.

When it comes to my core spending I stick with the Scotia Momentum Visa Infinite card for groceries, gas, drug store, and recurring bill payments, and the Capital One Aspire Travel World Elite MasterCard for everything else.

What I look for in a supplementary card is a rich bonus offer that is easy to attain so I don’t have to go out of my way to earn more points. I prefer a no-fee card, or else an offer that waives the annual fee in the first year. I also want to make sure the rewards are easy to redeem so I’m not stuck with unused points.

The American Express Air Miles Platinum card ticked all three of those boxes for me. Spending $500 within three months is very reasonable. The $65 annual fee is waived in the first year. And 2,000 Air Miles can easily be redeemed using the Air Miles eVoucher program, which I already use regularly.

Click here to take advantage of this credit card offer and enjoy 2,000 bonus Air Miles.