(CNN) —  

CNN Underscored reviews financial products such as credit cards and bank accounts based on their overall value, but does not review all financial companies or all available financial offers. We may receive compensation for sending traffic to partner sites, such as CreditCards.com, and this compensation may impact how and where links appear on this site.

Most American Express card members typically think of their Amex points as opportunities for amazing travel opportunities. While that’s true, there’s another lesser-known use for them: redeeming them for purchases at Amazon. And right now Amazon is offering a terrific promotion where you can actually save money by using your Amex points this way.

Right now, targeted American Express card members can save as much as 40% on their next Amazon purchase, for up to $40 in savings when you use Amex points to pay for at least a portion of your purchase at checkout through March 31, 2021. Other card members are getting 20% off for up to $30 in savings.

Targeted American Express card members can get this offer for 20% off at Amazon for up to $30 in savings, or another offer for 40% off for up to $40 in savings.
PHOTO: Amazon
Targeted American Express card members can get this offer for 20% off at Amazon for up to $30 in savings, or another offer for 40% off for up to $40 in savings.

Only some American Express card members are targeted for this promotion, so scoring it can be a little complicated. But we’re going to take you through it step by step to make sure you’re getting as much of a discount as possible when you’re shopping at Amazon.

How to save money at Amazon with your American Express card

To start, you must have an American Express card that earns Membership Rewards points. Amex cards that earn other types of rewards, such as cash back or airline miles, won’t work. But there are plenty of Amex cards that earn Membership Rewards points — a small sampling of them is at the end of this story.

Next, you’ll need to link your Amazon and American Express accounts. Add your American Express card as a payment method in your Amazon account, if you haven’t already. Then look for the option to enroll in “Shop with Points” under the “Your Account” tab, and click the “Enroll” button for the Amex card you just added.

You need to enroll your eligible Amex card in Amazon's "Shop with Points" program.
PHOTO: Amazon
You need to enroll your eligible Amex card in Amazon's "Shop with Points" program.

Once your accounts are connected, you’ll need to activate the offer by clicking on this link. Remember, this is a targeted promotion, so not everyone will be eligible for it — you could be targeted for any one of the offers or none of them. When you click on the link, if you see a message that you’re not eligible, then you’re unfortunately not targeted for this particular promotion.

But even if you’re not targeted, don’t give up hope. If you just enrolled in “Shop with Points,” you may need to wait 24 hours for Amazon’s records to refresh before knowing if you’re targeted, so check back in a day or so.

If you’re eligible, activate the offer by clicking on the “Activate now” button — the enrollment page will indicate your particular discount. You can then shop at Amazon as you normally would, though only products sold and shipped by Amazon are eligible for these discounts. Additionally, Amazon gift cards are excluded, though other third-party retailer gift cards sold by Amazon are eligible.

But wait! There’s one more step. When you’re ready to check out, you’ll want to make sure to select your linked American Express card as your payment method. Then you’ll need to use at least 1 point to pay for your purchase for the discount to apply.

When paying with Amex Membership Rewards points at Amazon, 1 point equals 0.7 cents. That’s not the best value you can get for Amex points. Frequent flyer website The Points Guy values Membership Rewards points as high as 2 cents each when redeemed for travel.

However, it’s important to note that you don’t have to pay for your entire Amazon purchase with points to get these discounts. In fact, you can use just 1 point and pay for the rest with your Amex card, and you’ll still see the discount applied to your order.

To pay with the minimum number of points required, enter $0.01 in the points section at checkout, which will apply just 1 point to your payment, You can use any number of points you want, but if you don’t make this change, Amazon may automatically apply the maximum number of points to cover the entire purchase, so you’ll want to make sure to update the amount before you place the order.

You can use any number of Amex points you want to get the discount.
PHOTO: Amazon
You can use any number of Amex points you want to get the discount.

Once you’ve applied at least 1 point to your payment, you’ll see the discount added to your order. You also don’t have to use your maximum savings all at once — the discount will apply to every order you place between now and March 31 until you hit the maximum combined savings for your particular offer.

Save on third-party gift cards too

While these discount offers don’t apply to Amazon gift cards, they do apply to many other third-party retailer gift cards that Amazon sells. And Amazon has literally hundreds of options, including retailers that might be useful right now, such as Netflix, DoorDash, Safeway and more.

Save money on your grocery bill by buying a Whole Foods gift card at Amazon with this promotion.
PHOTO: Amazon
Save money on your grocery bill by buying a Whole Foods gift card at Amazon with this promotion.

So even if you don’t find anything you want at Amazon before March 31, you can buy a gift card for yourself using the discount and bank the savings for later.

You can also pair these promotions with many of Amazon’s daily deals or any of its other money-saving offers, like saving $20 when you spend $60 on select beauty products.

What if you’re not targeted for these offers?

Even if you’re not targeted for these particular Amex promotions, offers like this typically resurface many times throughout the year, so keep on checking back. Amazon is also currently running similar promotions for Discover credit card holders, Chase credit card holders and Capital One credit card holders — read our guides on each of those offers to find out how to take advantage of them.

Amazon offered some incredibly lucrative promotions throughout 2020 — some of the best we’ve ever seen. So as we get further into 2021, keep your eyes peeled for any other savings that may pop up, and if you’re targeted for any of these offers, make sure you use them before they expire on March 31.

If you don’t currently have an eligible Amex card, here are several options you might consider:

Amex personal cards:
American Express® Gold Card
Amex Everyday® Credit Card from American Express
The Platinum Card® from American Express

Amex business cards:
The Blue Business® Plus Credit Card from American Express
American Express® Business Gold Card
The Business Platinum Card® from American Express

Also, make sure you read our guide to the best credit cards for Amazon to be sure you’re using the right card when you buy at Amazon.

Check out CNN Underscored’s list of 19 of our favorite products under $15 on Amazon.

Find all the latest personal finance deals, news and advice at CNN Underscored Money.