Visa and Mastercard: The Hidden Glue Behind Every Card Swipe
What do Visa and Mastercard do? An intro to card networks
Visa and Mastercard don't issue your card, lend you money, or print plastic. They run the invisible networks that connect cardholders, issuers, merchants, and acquirers. This deep dive explains their four core jobs: routing transaction messages like telecom switches, settling billions in daily payments, setting interchange fees that shape rewards and merchant costs, and enforcing a 923-page rulebook with a $600 arbitration fee. It also reveals why issuers keep the biggest cut and why the EU's fee caps explain its lack of rewards cards.
Arbitration is not a fair system, but it is an efficient one.
- losvedir
I play the credit card "game" because I hate feeling like I'm leaving money on the table, but I really wish I didn't have to. Some degrees of fees make sense, to run the network, and handle fraud, but it's ridiculous that people have this sense that shopping should somehow fund your vacation.
Where I am it's increasingly common to see credit card fees when checking out. I get it, because merchants are being charged 3-5% of their total revenue. I wish there was a low fee credit card network that merchants didn't charge a fee for, so I could continue the simplicity of digital payments but opt out of this crazy Visa Infinite rewards accounting boondoggle.
- alwaysmrno
Visa and Mastercard are legacy companies providing a service that is outdated in the modern world.
China generally doesn't use Credit cards because when they "Modernized" there was new technology and infrastructure so you didn't need a nosey middel-man to handle the transaction. Instead they use apps.
Scandinavia is hopefully moving away from these card-providers soon. They have the bankaxept system that works flawlessly in their area and have started introducing Apps for payments and microtransactions.
For some reason some of the apps require a debit-card, but i hope they will drop that requirement soon.
I just hope these leeches on society will sone go bankrupt.
- maelito
Well I don't really know what they do, but what I know is that Visa transactions costs are 0,22 € out of a payment of 1 €, Mastercard's is 0,23 €, and the French CB network is 0,17 €.
All of them do the same : ensure I get the money from the customer. Of course it's a larger project to run this in the whole world, but shouldn't it scale to less along with the number of billions of customers instead of the other way round ?
This is an insane amount of money. They killed micro-transactions, they killed the business model of the Web in favor of ads, the only popular way to do microtransactions right now.
- techdmn
I remember reading a comment here a while back about merchants being offered a discount on the processing fee if they also transmitted detailed data about the purchase (essentially the data that would be on the receipt). That data could then be resold on to advertisers. Does anyone remember this or have links to more data? (Not having much luck with search, maybe I'm hallucinating the whole thing.)
- 1a527dd5
There used to be an account on Twitter that was heavily involved in this industry. Every now and then I'd glean some slightly useful information from their posts. My favourite one being "the name verification isn't a thing - you can enter anything". So I've been doing that ever since and it's _always_ passed.
- TheGoodBarn
If anyone is interested in this topic from a historical standpoint, the Acquired episode on Visa is phenomenal: https://www.acquired.fm/episodes/visa
- gatestone
I find this interesting as a technology, as a business process, and above all as a system for managing trust on a global scale across different jurisdictions. In a sense, the credit card system accomplishes something that even the UN, international law, Interpol and military mights cannot do: it enables individuals to enter into trustworthy global agreements with minimal effort and risk, and at very low transaction costs.
- cemoktra
Accurate summary. Had been working on issuing side for almost 5 years. Some of the issuing providers offer really good APIs, some of them are really bad. But overall the card networks are easier to implement than parsing banking data directly
- 1970-01-01
>The merchant pays 2.5%
The best way to pay for poor services already rendered and move on with life is to simply pay via card. Didn't like that haircut? Terrible food at the restaurant? Hold onto your cash and slip them the card.
- vavooom
I like the vibe and overall writing style of this blog! Keep up the short little segments. Charcoal Grill and Doing Things Ten Times are my favorites:
* https://tautology.town/2026/02/14/learning-charcoal-grilling...