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Earn Miles With Credit Cards (Multi-Program Charge Cards)

Sooner or later, every frequent flyer finds himself having miles in one program but needing them in another. That conundrum brings you face-to-face with the stubborn fact that, generally speaking, miles are not transferable. And that in turn leaves many frustrated mileage mavens wondering why there exists no universal rewards currency—miles or points that can be easily exchanged among various programs.

In the realm of airline and hotel programs, there are compelling reasons why a widely convertible currency doesn’t make good economic or marketing sense. But those considerations do not apply in the universe of charge cards, where there is in fact something very much like a universal rewards currency.

Actually, there are two such currencies— American Express Membership Rewards points and Diners Club Rewards points—though they are not themselves interchangeable. And because these universal currencies offer more flexibility and safety than miles or points, using the American Express and Diners Club charge cards could just be the best of all possible worlds.

How it works: Convertible points

Unlike the co-branded credit cards issued in conjunction with most airline and hotel programs, which reward consumers with miles or points exclusively in the affiliated program, the Amex and Diners programs, Membership Rewards and Club Rewards respectively, compensate card users with points that are convertible into a wide range of airline miles and hotel points.

American Express cardholders earn two Membership Rewards points for every one dollar purchased with the card “at qualifying stand-alone supermarkets, drugstores, gas stations, home improvement stores, the U.S. Postal Service, and for payments for your wireless phone bill.” Other charges earn one point per dollar. Once earned, points may be exchanged for miles in 11 airline programs and points in five hotel programs. In most cases, the points-to-miles exchange rate is 1:1. (American Express has a variety of products from which to choose. For this article, the focus is on their Preferred Rewards Green Card because it offers the most robust points-earning and is therefore most likely to appeal to the mileage-earning set.)

With the Diners Club card, consumers earn two Club Rewards points for every dollar in purchases. But when it comes time to convert points to miles, two points equal one mile; so the effective dollar-to-mile exchange rate is 1:1. Points are exchangeable into miles and points in the programs of 26 airlines and nine hotels.

The following table compares features and benefits of the two cards:

American Express
Preferred Rewards
Green Card
Diners Club Card
Annual card fee $110 $95
Enrollment bonus N/A 12,000 miles
Miles earned per $1 charged 2 for “everyday purchases”;
1 for others
Airline partners Aeromexico, All Nippon, Continental, Delta, El Al, Global Pass, Hawaiian, Mexicana, Southwest, US Airways, Virgin Aer Lingus, Air Canada, Air France, Alaska Airlines, America West, American, Asiana, British Airways, Continental, Delta, El Al, Frontier, Hawaiian, Global Pass, Iceland Air, Korean, Mexicana, Midwest, Northwest, SAS, South African Air, Southwest, Thai, United, US Airways, Virgin
Hotel partners Best Western, Hilton, Marriott, Priority Club, Starwood Baymont, Best Western, Choice, Hilton, Hyatt, Marriott, Priority Club, Ramada, Starwood
Conversion fee None 95 cents for every 1,000 points converted to miles
Mile-to-mile conversion No Yes
Merchant acceptance 7.5 million 8.5 million

Annual fee

At $110 and $95 per year for the Amex and Diners cards respectively, the cost of ownership is significantly higher than for the airline and hotel rewards cards covered in previous installments of this series.

The added flexibility of convertible points together with the higher levels of customer service arguably justify the price premium.

Enrollment bonus

Amex is almost alone among rewards-card issuers in not offering a bonus for signing up for the card. Diners offers a 24,000-point bonus (2,000 points awarded monthly for the first year), which you can transfer into 12,000 miles.

Mileage-earning rate

For consumers who are able to channel their charge activities to select retailers, as defined above, the ability to earn double points with the Amex card is a benefit with significant added value.


As reflected in the table, Amex allows Membership Rewards points to be converted into the programs of 11 airlines and five hotels; Diners points are exchangeable into 26 airline and nine hotel programs.

Looking beyond the numbers, conspicuously missing from the Amex partner roster are the world’s two largest airline programs, American’s AAdvantage and United’s Mileage Plus.

Conversion fee

In 2002, Diners began imposing a “handling fee” of $0.95 for every 2,000 Club Rewards points converted to miles (equal to 1,000 frequent flyer miles). So when redeeming enough points for a free domestic coach ticket—50,000 points, which equate to 25,000 miles—the fee would be $23.75.

Amex imposes no such fee.

Billing cycle

Both the Amex and Diners products are charge cards, as opposed to credit cards, meaning that the balance must be paid off completely. There is a difference, however, in the length of time cardholders have to discharge their accumulated debt.

Whereas holders of the Amex Green card must adhere to a traditional monthly billing cycle, paying in full by the end of the following month, Diners cardholders may take two billing cycles, up to 62 days, to pay.

Other awards

Both programs offer members extensive award options over and above airline miles and hotel points, including gift certificates, merchandise, and services. And to take it a step further, both also offer personalized awards, allowing cardholders to suggest awards of their own choosing, which the card company will price in points and deliver if the customer agrees and has sufficient points to redeem the award.

Mileage exchange

In addition to points-to-miles conversions, Diners offers its members the ability to exchange American and United miles into Diners Club points. Taken together, the two functions—miles-to-points and points-to-miles—allow cardholders to exchange American or United miles into miles in the programs of 26 other airlines.

The Joy of Miles:

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While there is substantial conversion loss (e.g. 10,000 United miles convert to 5,000 Delta miles), it is still less than the loss associated with conversions or through Hilton HHonors’ Reward Exchange.

Merchant acceptance

In years past, the conventional wisdom was that Amex and Diners Club cards were great, as long as consumers were willing to put up with the inconvenience of a limited network of retailers that accepted the cards for payment. Visa and MasterCard, by contrast, were accepted virtually everywhere.

Lately both Amex and Diners have made concerted efforts to increase the number of retailers that accept their cards, thereby narrowing the gap with Visa and MasterCard. Amex now widely promotes card use for “everyday purchases,” and Diners has expanded from Brooks Brothers and three-star dining establishments to include the Gap, Old Navy, and even 7-Eleven.

According to a recent Nilson Report, the current worldwide merchant-acceptance numbers are as follows:

  • Visa/MasterCard: 29.2 million
  • Diners Club: 8.5 million
  • Amex: 7.5 million

Neither Amex nor Diners would disaggregate the merchant numbers, but my personal sense is that the Amex merchant network is greater than Diners’ within the U.S., but smaller than the Diners network elsewhere in the world.

Safe haven for miles

In these troubled times for the airlines, there’s yet another reason to keep one’s credit-card earnings in a neutral currency: safety. If a failed airline liquidates its assets and simply voids the miles in its loyalty program, points in the programs of Amex and Diners would be unaffected. Unlike the airlines, both Amex and Diners (a subsidiary of mighty Citibank) are in tip-top financial shape.


These are both solid products, either of which might legitimately lay claim to the title of the Swiss Army knife of reward cards. And if you don’t mind paying the higher annual fees and do not need to carry a balance from month to month, these cards can be a better choice than regular airline- or hotel-affiliated credit cards.

Clearly, each card has its distinctive strengths and weaknesses. Diners offers an enrollment bonus; Amex offers double points for “everyday purchases.” Amex doesn’t charge a fee to convert points to miles; Diners allows conversion from American or United miles into a host of other programs. And so on.

For many frequent travelers, who use charge cards to selectively augment their earning in airline and hotel programs, the choice between these two cards is simple: Use the card that will allow you to convert points into the travel programs in which you already participate.

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