How I Save Money With Cash Back: The App and Cards I Use

Here’s how I save money with cash back: I match every purchase to the card or app that pays the most for it. Gas goes on one card, online shopping on another and everything else on a flat 2% card. Adding up my reviews, that’s $858.58 in cash back and sign-up bonuses so far, and every number comes with a screenshot.

None of this means spending more to earn rewards. It’s about paying for things you’d buy anyway with the card that pays the most for them. That total doesn’t even include my PayPal Debit Card or PayPal Credit Card rewards, which I haven’t added up in a review.

My Cash Back Stack at a Glance

Here’s what I use for each kind of purchase:

What I’m buying	What I use	Cash back
Gas	PayPal Debit Card + Upside	5% + Upside’s cents per gallon
Gas, if you drive for Amazon Flex	Amazon Flex Debit Card	Up to 6%
Online, with PayPal checkout	PayPal Cashback World Mastercard	3%
Everything else, including Amazon	Wells Fargo Active Cash or PayPal Credit Card	2%
Amazon, if you have Prime	Amazon Store Card	5% (nothing without Prime)

How I Save Money With Cash Back on Gas

Gas is where I save money with cash back the fastest, because I can stack two rewards on the same fill-up: a cash back card and an app. The average household spent about $2,411 on gas in 2024, according to the Bureau of Labor Statistics. At 5%, that’s about $120 a year.

PayPal Debit Card: 5% on Gas

The PayPal Debit Card is a free debit Mastercard with no credit check. Each month, you pick one category and get 5% cash back on up to $1,000 of spending in it (here are PayPal’s terms). I pick Fuel every month. A $40 fill-up earns 200 points, which is $2.

Points usually show up by the next day, and I redeem them to my PayPal balance.

Upside: Cash Back on Top

Then I add Upside. I claim a gas offer in the app before I fill up, pay with my PayPal Debit Card and get cash back from both. Upside has paid me $121.56 so far, mostly on gas, plus a few grocery offers.

One catch: cashing out less than $10 to your bank costs a $1 fee, so I wait until I have at least $10.

Amazon Flex Debit Card: Up to 6% (Flex Drivers Only)

If you drive for Amazon Flex, the Amazon Flex Debit Card beats both. It pays up to 6% cash back on gas at Flex Rewards Level 4, and it has paid me $248.58 since April 2025, $242.37 of it from gas. Only Flex drivers can get it, and the levels reset every quarter, so most part-time drivers end up at 2% or 4% instead.

Want to see what this could save you? Try my gas cash back calculator.

Online Shopping: 3% With PayPal Checkout

Anywhere I can check out with PayPal, I use the PayPal Cashback World Mastercard. It pays 3% cash back with PayPal checkout and 1.5% everywhere else, so I only use it where the PayPal button shows up, like eBay, Steam, Nintendo and GameStop. It has earned me $192.18 since May 2025.

On $500 of online shopping, a 2% card earns $10. This card, with PayPal checkout, earns $15.

Everything Else: a Flat 2% Card

For everything that isn’t gas or PayPal checkout, including Amazon, I use a card that pays a flat 2% on everything, with no categories to track. I have two:

• Wells Fargo Active Cash: 2% cash back on everything, plus a $200 bonus for spending $500 in the first 3 months. By May 2026, I’d redeemed $216.26: the $200 bonus plus $16.26 in cash back.
• PayPal Credit Card: also a flat 2%, with no sign-up bonus. I was approved in April 2026 and used it the same day.

Both pay the same, so I just use whichever one. Keeping both gives me a bigger total credit limit.

Sign-Up Bonuses: The Biggest Wins

My fastest cash back came from sign-up bonuses: $200 from the Wells Fargo Active Cash and an $80 Amazon gift card from the Amazon Store Card. That’s $280, about a third of my total, for spending I was going to do anyway.

The Amazon Store Card is the one I wouldn’t get for the cash back. It pays 5% on Amazon only if you have Prime. I don’t, so its rewards balance has been $0.00 the whole time. I got it for the $80 gift card.

How to Start Saving Money With Cash Back

If you’re starting from zero, here’s the order I’d follow to save money with cash back. Each step sets up the next one.

1. Get a debit card that pays cash back. There’s no credit check. The PayPal Debit Card’s 5% on gas is where I’d start. Here’s how to get your first debit card.
2. Add Upside for gas and groceries. It works with any card, so you earn twice on the same purchase.
3. Build credit with a secured card. My first credit card was a Discover secured card with a $200 deposit. Eight months later, I got the deposit back and an $1,800 limit. Here’s how to get your first credit card.
4. Get a flat 2% card once your credit is a few years old. Wells Fargo denied me in 2024 because my credit history was too short. Two years later, they approved me, with a $200 bonus.
5. Add a 3% card if you shop with PayPal checkout. Use it only where the PayPal button shows up, and your 2% card everywhere else.

What I’ve Learned

Match the card to the purchase. No single card wins everywhere. 5% on gas, 3% with PayPal checkout and 2% on everything else beats putting it all on one card.

Pay your credit cards in full. A 29.64% APR, like the one on my PayPal Credit Card, wipes out 2% cash back fast. Cash back only works on money you’d spend anyway and can pay off right away.

Don’t apply too early. My Wells Fargo denial taught me that. Waiting until my credit history was older got me approved for both 2% cards in 2026.

It’s small money that adds up. A dollar or two per fill-up doesn’t feel like much, but it turned into hundreds of dollars without changing what I buy.

My Verdict: Is Saving Money With Cash Back Worth It?

Yes. Saving money with cash back is the easiest money I make, because it comes from spending I was already doing. Start with a debit card and Upside, build your credit, then add a 2% card and a 3% card when you’re ready.

Once you’re keeping more of what you earn, put it to work. Here’s how to start investing with little money, the way I started with $200. And if you need more money coming in first, see how I make money online.

FAQ

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I’m not a licensed financial advisor. This guide is based on my own accounts and each card’s terms when I wrote my reviews. Rewards, bonuses and terms change, so check the current terms before you apply. This guide isn’t sponsored, and it doesn’t use affiliate links.