# My bank offers 10.5% interest **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [June 10, 2026, 5:49pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803 "2026-06-10T17:49:03Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [June 10, 2026, 8:41pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/21 "2026-06-10T20:41:29Z")
Let’s run some numbers. Say you use your debit card 30 times in a month (which is a lot more than I do, but isn’t unreasonable). Assume the average rounded amount is $0.50, so you’re depositing $15/month into the account. At a 10.5% rate compounded monthly, you end up with a bit over $10.50 in interest at the end of the year. If you instead put it in a regular savings account at 4% interest, you’d get about $4.00. So this new account is netting you around $6-7 in a year. If there are no restrictions on the money, then go for it – free money is free money. But no one’s getting rich off it, and the bank isn’t losing money, given they probably made $300+ in swipe fees off you. ETA: of course, if you leave it in there for many years ( **and the bank doesn’t restrict how long that rate lasts** ), it continues to compound. At the end of five years, you’ve netted around $70. Don’t touch your money for 20 years or so, and you might even get $1000 out of it. ---
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [June 10, 2026, 8:56pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/22 "2026-06-10T20:56:50Z")
I couldn’t find it easily on the Century Federal Credit Union website, but Google states that > Details for the **[Century Federal Credit Union Savings Jar](https://www.cenfedcu.org/products-services/cards/debit-atm/savings-jar)** program: - **Earning Limits:** The high 10.47% Annual Percentage Yield applies specifically to the first $500 of your Savings Jar balance. - **Remaining Balance:** Any amount in your Savings Jar over $500 generally earns standard savings dividend rates. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [June 10, 2026, 9:06pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/23 "2026-06-10T21:06:10Z")
Thanks for finding that. So you’re topping out at around $30 net/year. Only 300 years to hit $1000! ---
**Author:** ![Left\_Hand\_of\_Dorkness](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/left_hand_of_dorkness/32/7156_2.png) [@Left\_Hand\_of\_Dorkness](https://boards.straightdope.com/u/Left_Hand_of_Dorkness)\ **Post date:** [June 10, 2026, 9:49pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/24 "2026-06-10T21:49:31Z")
> [@TroutMan](#): > > So you’re topping out at around $30 net/year. Only 300 years to hit $1000! 30x300=1000? ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [June 10, 2026, 9:54pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/25 "2026-06-10T21:54:53Z")
🤦 You want someone good at math, go to a bank. Between that and the plan to pay $100 in 20 payments of less than $1, you’re getting some awesome financial advice in this thread. ---
**Author:** ![Atamasama](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atamasama/32/12961_2.png) [@Atamasama](https://boards.straightdope.com/u/Atamasama)\ **Post date:** [June 10, 2026, 10:21pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/26 "2026-06-10T22:21:27Z")
> [@TroutMan](#): > > See my note above - all the banks/CUs I saw that offer this restrict it to debit card transactions. I’ve had a feature just like it for many years called “Keep the Change”. Any debit purchase I make is rounded up to the next dollar and the pennies are put into a savings account. I get interest on that account, and despite not making regular deposits into it myself (though I can any time I want) I have thousands of dollars in it. My APY on that account is 0.01% though, a far cry from the 10% in the OP. It’s not an investment account as much as just a place to park money. I only make maybe 2 cents a month on average; practically nothing. It’s just a way to set aside extra money as an emergency fund or whatever. I hope to never have to tap into it, and haven’t for many years. I looked it up on Google, and that tiny rate is pretty typical for the large brick-and-mortar banks. My bank is Bank of America by the way before anyone asks. ---
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [June 10, 2026, 11:17pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/27 "2026-06-10T23:17:39Z")
> [@Czarcasm](#): > > What bank is this? Century Federal Credit Union in the Cleveland area. ---
**Author:** ![Elmer\_J.Fudd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/elmer_j.fudd/32/1211_2.png) [@Elmer\_J.Fudd](https://boards.straightdope.com/u/Elmer_J.Fudd)\ **Post date:** [June 11, 2026, 2:27am UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/28 "2026-06-11T02:27:08Z")
It sounds like some store coupons back in the day. The system _can_ be gamed, but 99% of people in the program aren’t willing to devote the time and energy to do so. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [June 11, 2026, 2:40am UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/29 "2026-06-11T02:40:17Z")
How would you game this system? ---
**Author:** ![Elmer\_J.Fudd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/elmer_j.fudd/32/1211_2.png) [@Elmer\_J.Fudd](https://boards.straightdope.com/u/Elmer_J.Fudd)\ **Post date:** [June 11, 2026, 2:44am UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/30 "2026-06-11T02:44:07Z")
The multiple micro transactions suggested above, barring any hidden restrictions. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [June 11, 2026, 2:45am UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/31 "2026-06-11T02:45:55Z")
It’s for debit card transactions only, not online payments. ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [June 12, 2026, 4:55pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/32 "2026-06-12T16:55:00Z")
> [@TroutMan](#): > > How would you game this system? When you go to the grocery store buy everything as a separate txn\> rather than pay for everything all at once. However, even if the store is slow & there’s not a ~~line~~ angry mob behind you it’s still going to take you longer overall to check out. Is it really worth the time for a couple of pennies? ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [June 12, 2026, 5:20pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/33 "2026-06-12T17:20:25Z")
The merchant won’t let you do that. For every extra swipe that’s earning you a penny in interest, they are paying an extra $0.30 in fees. If you find a merchant that lets you get away with it, you could probably think up more lucrative scams to take advantage of their stupidity. ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [June 12, 2026, 7:39pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/34 "2026-06-12T19:39:16Z")
> [@TroutMan](#): > > If you find a merchant that lets you get away with i Many a grocery store have one employee for the entire self-checkout, which can be two or three banks in some stores. If your terminal isn’t flashing the light that you’re stuck I doubt they’d come over all that quickly. Even if they do, if it’s a HS kid I doubt they’d catch on to what your doing. Hell, when I go to the cashier, I lay out stuff on the conveyer belt how I want it packed, sometimes creating a gap, say between the cold stuff & the non-perishables so that I get all the cold stuff to bag first in one bag as opposed to needing to unpack them all as soon as I get home. I’ve had cashiers ask me if that’s a separate order over a maybe 6" gap, so a given cashier might even be thinking that & not even realize what you’re doing. ---
**Author:** ![Elmer\_J.Fudd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/elmer_j.fudd/32/1211_2.png) [@Elmer\_J.Fudd](https://boards.straightdope.com/u/Elmer_J.Fudd)\ **Post date:** [June 12, 2026, 7:43pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/35 "2026-06-12T19:43:39Z")
If the restriction relies on the checkers, just use self-checkout. If there is one, enforcement will almost certainly be automated. I wouldn’t be surprised if there is no swipe limit, relying on the fact that few people would go to the trouble. ---
**Author:** ![Dorjan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dorjan/32/12440_2.png) [@Dorjan](https://boards.straightdope.com/u/Dorjan)\ **Post date:** [June 12, 2026, 7:55pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/36 "2026-06-12T19:55:52Z")
Let me make sure I understand this right. If I use my debit card to pay 4.60 for something, my bank will deposit .40 into my savings jar account. This $ is coming from my checking account, correct? ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [June 12, 2026, 8:09pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/37 "2026-06-12T20:09:57Z")
So you find a grocery store that doesn’t monitor their self-checkouts and won’t suggest you move along after doing this multiple times. (Given their profit margin and swipe fees, I doubt you will get away with this for long). Let’s say you attempt to sequence your items to maximize the change, so for every swipe you’re putting $0.80 in your 10% savings account. After a year, that $0.80 is now $0.88 for a profit of 8 cents. It probably takes 1-2 extra minutes for each transaction. Congrats, you’ve found a scam that pays $2 to $5/hour, and tops out at $30/year. ---
**Author:** ![Heracles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heracles/32/487_2.png) [@Heracles](https://boards.straightdope.com/u/Heracles)\ **Post date:** [June 12, 2026, 8:21pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/38 "2026-06-12T20:21:56Z")
Yes, that’s the nature of the round-up programs I’ve seen so far. It’s _the customer’s money_ that gets stashed into the customer’s magic piggy bank, just in amounts that count as “loose change”. I doubt this one is different. ---
**Author:** ![Munch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/munch/32/5281_2.png) [@Munch](https://boards.straightdope.com/u/Munch)\ **Post date:** [June 12, 2026, 8:22pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/39 "2026-06-12T20:22:37Z")
> [@Dorjan](#): > > This $ is coming from my checking account, correct? Yes. And the money in that account earns 10.4% APY, which comes from the bank. ---
**Author:** ![Elmer\_J.Fudd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/elmer_j.fudd/32/1211_2.png) [@Elmer\_J.Fudd](https://boards.straightdope.com/u/Elmer_J.Fudd)\ **Post date:** [June 12, 2026, 8:23pm UTC](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803/40 "2026-06-12T20:23:36Z")
> [@TroutMan](#): > > It probably takes 1-2 extra minutes for each transaction. Congrats, you’ve found a scam that pays $2 to $5/hour, and tops out at $30/year. Which is pretty much what I said. > [@Elmer\_J.Fudd](#): > > I wouldn’t be surprised if there is no swipe limit, relying on the fact that few people would go to the trouble. [Previous page](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803.md?page=1) [Next page](https://boards.straightdope.com/t/my-bank-offers-10-5-interest/1030803.md?page=3)