There used to be a Visa credit card code lookup website that I used, but it's since closed down.
I am currently trying to figure out what stores would code as 5310 discount stores which is a category on the Redstone signature visa.
I found this website:
https://awardwallet.com/en/merchants
You can type in a store, and it will tell you a category, but not the MCC number. I have not found a single store that comes up as "discount store". I've tried Walmart, Target, Dollar General, Big Lots, Family Dollar, TJ Maxx.. some of these come up on that lookup tool as unexpected. Big Lots is listed as a wholesale club, Dollar General is listed as Merchandise & Supplies - General Retail. I'm not particularly confident in a lookup tool that classifies Big Lots the same as Costco. 
Maybe my google search terms are terrible, but I can't find a list anywhere of what sorts of stores code as 5310.
Are there any alternatives to the now-defunct Visa lookup tool?
@FireMedic1 wrote:What card are you talking about?
The Redstone Federal Credit Union Signature Visa:
https://www.redfcu.org/personal/credits-cards/visa-signature/
5% on gas & restaurants, 3% on groceries, discount stores, wholesale clubs, utilities, phone & streaming services, 1.5% on everything else.
I have a pretty good idea on the other categories, but I don't know what a "discount store" is. I've read that some Walmarts and Targets will code that way, but some won't. I'm trying to figure out if my local ones will, and what other possible stores that I'm not thinking of might be included. Redstone does not specify 5310, that's just the code that came up when I googled for the MCC for discount store, so I guess it's possible that it's not that, but that seems the most likely code.
It seems your only options is to test it out. Does this CU itemize and list charges along with cash back earned? Chase and BOA do.
I am thinking about applying for this credit card. Are there any tips you would like to share?
Unfortunately, the web interface and statements from Redstone are pretty bad. They don't indicate what rate the reward was for each charge. There's just a total of how many points you earned that month. With this card, it's going to be really difficult to figure out what rate you got for what charge and if the total doesn't add up to what you thought it was, you don't know which charge was the culprit.
As for tips for the card, I believe you have to be a member to apply because it asked for my member number in the app. There are other threads showing ways you can join.
Here is my approval thread with details of my app. I had to recon to get it:
@dlister70 - Did you ever figure out what merchants codes as a discount store? I've been searching to find the same with no success.
Starting Score: 800
@Anonymous @dlister70 Here is how you find out how the transaction is coded click on the plus sign next to the transaction
@AndySoCal wrote:@Anonymous @dlister70 Here is how you find out how the transaction is coded click on the plus sign next to the transaction
And that's great for once you have made the transaction. OP is trying to answer the question "If I go to store X, will it code as a discount store? (And if not, which stores will)."