The Hidden Cost of Card Payments: Why Merchants Lose 3-7%
The real cost of a card payment goes well beyond the headline rate. Here is how the fee stack builds up, and what a transparent alternative looks like.
The Hidden Cost of Card Payments: Why Merchants Lose 3-7%
By Greggar Deterville, Founder and CEO, KAELUM Technologies Ltd | 18 February 2026
Most merchants know their headline card rate. Far fewer know what card payments actually cost them once everything is added up. The headline rate is where the bill starts, not where it ends.
The Fee Stack
A card payment passes through several hands, and each takes something.
- Interchange, paid to the card issuer. In the UK and EU, consumer debit is capped at around 0.2% and consumer credit at around 0.3%, but commercial cards and cards issued outside the capped regions can cost far more.
- Scheme fees, paid to the card network itself, often in many small line items that are hard to compare.
- Acquirer and processor margins, the provider's own share, frequently presented as a single blended rate.
- Currency conversion, where the acquirer's margin on top of the mid-market rate quietly adds to every cross-border sale.
For a domestic merchant on a simple blended rate, the total may look modest. For e-commerce merchants with international customers, the stack climbs quickly.
The Costs That Never Appear on the Rate Card
Then come the costs that are not fees at all.
Chargebacks. When a customer disputes a payment, the merchant can lose the sale, pay a chargeback fee and spend staff time on evidence, often for weeks. High dispute rates can trigger card scheme monitoring programmes, higher fees, or the loss of a merchant account altogether.
Settlement delay. Card funds can take days to arrive. For businesses with tight cash cycles, that delay is a permanent working capital gap.
Taken together, interchange, scheme fees, processing margins, conversion, disputes and delay can push the real cost of accepting cards to somewhere between 3% and 7% of revenue for many merchants, and higher in categories with frequent disputes. For a business running on single-digit margins, that is not a detail. It is the difference between growth and standing still.
A Different Kind of Payment
KAELUM is an Ai-native digital commerce currency platform. Customers pay in KAE, a commerce currency fixed at £0.20 per unit, and receive a discount of 6% or more on goods when they spend it with participating merchants. Each merchant sets its own rate, at or above the minimum. A 4.5% platform fee applies.
What changes for the merchant is not that payment becomes free. It is that the cost becomes visible, and that it buys something:
- One transparent platform fee instead of a stack of scheme, interchange and margin lines.
- Customers who are looking for you. People holding KAE can only spend it with KAELUM merchants and creators, so joining the network puts you in front of buyers already looking for places to spend.
- Disputes handled through KAELUM's own dispute and refund centre. KAE payments do not run through card schemes, so card scheme chargeback fees and monitoring programmes do not apply.
- Fraud protection on every payment. K.A.T.E., powered exclusively by Claude from Anthropic, checks every transaction, and sensitive actions pass human approval gates.
- Commerce intelligence. Merchant analytics and K.A.T.E.'s guidance on pricing, discount rates and retention.
Where KAELUM Stands
KAELUM is built and in pre-launch testing. KAELUM is pre-launch and is working towards the appropriate regulatory permissions before it takes any customer funds.
Card payments will not disappear, and KAELUM is not trying to make them. It is built to give merchants an additional way to get paid, where the cost is clear and the value comes back to them.
Join the KAELUM waiting list at kaelum.app/Waitlist to be ready from launch.
Crypto is powered by Blockchain. KAELUM is powered by Ai.
KAELUM Technologies Ltd is registered in England and Wales (Company No. 16681154). KAE is a digital commerce currency and is not a cryptocurrency, security or investment instrument. Fee figures are general industry ranges and vary by provider, card type and sector. This article is for informational purposes only and does not constitute financial advice. Contact: info@kaelumtechnologies.com | kaelum.app