Insights

Capital One x Discover: What the Debit Migration Means for Merchants

Card Fees, Industry News

Quick Answer: Following Capital One’s acquisition of Discover, Capital One debit cards are migrating from Mastercard to Discover’s network. For merchants, this means debit transactions on Capital One cards that previously routed through regulated Mastercard rates will increasingly route through Discover — which prices above the Durbin cap. Merchants should monitor their BIN data, review least cost routing settings, and prepare for higher effective debit costs on Capital One cards.

Back in May 2025, Capital One finalized its merger with Discover, becoming the 6th-largest financial institution in the United States by asset size. This development has already begun to impact merchants. 

Discover operates on a closed-loop network, meaning it functions as both the issuer and acquirer in the payments lifecycle. Because of this structure, Discover (and American Express) are exempt from the Durbin Amendment, which caps debit interchange rates for large financial institutions at 0.05% + $0.22. 

Learn more about debit routing.

Following the merger, Capital One can now leverage Discover’s closed-loop network to bypass these debit interchange caps and charge merchants higher debit interchange rates. Since June, Capital One has started migrating its existing debit volume, largely concentrated on the Mastercard network, to Discover’s network. They plan to finish this debit migration by the end of 2025. 

To provide a few cost increase examples, Discover’s current debit interchange rates are 1.10% + $0.16 for Card Present, 1.20% + $0.05 (MCCs 4814 and 4899) for Recurring, and 1.75% + $0.20 for Card Not Present transactions. Based on our break-even analysis, unless your average transaction value is below $5.71, $14.78, or $1.18, respectively, your business will pay more in interchange fees under these new rates. 

If you’d like to learn more about the Capital One debit migration and its broader merchant implications, you can read our earlier article and watch our webinar here. 

Financial Impact Example: 

Consider a merchant in the telecommunications industry operating under MCCs 4814 or 4899 with a recurring payments business model. The merchant processed $1.0B in annual total card payments across 50million transactions. Of this, 12% of total volume ($120M) and 6 million transactions are attributed to Capital One cards, with 20% ($24M) and 1.2 million transactions representing debit activity. 

If 39% of the Capital One debit volume and transactions shifted from the regulated Durbin debit interchange rate to Discover’s unregulated PSL – Recurring Payments rate (1.20% + $0.05), your financial impact would be an annual increase of approximately $28K in fees.  

Interchange Fee Calculation (39% of Capital One Debit Volume Shifted to Discover): 

  • New Discover Unregulated Debit Fees: 39% x ((24M sales x 1.20% rate percent) + (1.2M transactions x 0.05 rate per item)) = $135,720 
  • Old Durbin Regulated Debit Fees: 39% x ((24M sales x 0.05% rate percent) + (1.2M transactions x 0.22 rate per item)) = $107,640 
  • Net Increase in Fees: $135,720 – $107,640 = $28,080 

If 100% of the Capital One debit volume and transaction shifted from the regulated Durbin debit interchange rate to Discover’s unregulated PSL – Recurring Payments rate (1.20% + $0.05), your financial impactwould be an annual increase of $72K in fees. 

Interchange Fee Calculation (100% of Capital One Debit Volume Shifted to Discover): 

  • New Discover Unregulated Debit Fees: (24M sales x 1.20% rate percent) + (1.2M transactions x 0.05 rate per item) = $348,000 
  • Old Durbin Regulated Debit Fees: (24M sales x 0.05% rate percent) + (1.2M transactions x 0.22 rate per item) = $276,000 
  • Net Increase in Fees: $348,000 – $276,000 = $72,000 

The $72K net increase in fees represents a 26% rise in Capital One debit interchange costs based on the merchant’s volume and transaction assumptions. While this accounts for only 0.007% of the total annual card payment volume, shifts like these can still affect bottom-line savings and should be monitored closely.  

If you would like to perform similar calculations for your business, make sure to account for your MCC(s), Capital One debit share, and Card-Present versus Card-Not-Present mix (if your MCC is ineligible for Discover’s industry-specific rates). If unavailable, you can assume Capital One debit represents roughly 2% of total debit volume based on market share data. 

Recent Developments: 

What began in June and July as the migration of only a few thousand dollars in debit volume has rapidly evolved into millions being transferred to the Discover network each week through the end of October. Three new Discover BINs that were receiving the bulk of the debit migration volume include 601141, 601144 and 601146, with most of the activity concentrated in 601141.  

For these BINs, Discover will appear as the issuer, but they represent Capital One-issued debit cards processed through the Discover network. These cards can be distinguished by the Discover, Diners Club, or Pulse logos displayed on the card (see image below). 

Insights provided by: Evan Andersen, Payments Consultant

Frequently Asked Questions

Why does the Capital One-Discover merger matter for merchants?

Capital One is the largest debit card issuer in the U.S. As it migrates debit volume from Mastercard to Discover, merchants who previously benefited from Durbin-regulated Mastercard debit rates on Capital One cards will see those transactions shift to Discover debit, which is not subject to the same regulatory cap. This can meaningfully increase effective debit costs for high-volume merchants.

What should merchants do right now to prepare?

Start by setting up a BIN migration watchlist to track Capital One-to-Discover shifts weekly. Confirm your gateway or processor is attempting least cost routing wherever a second unaffiliated network is enabled. Refresh your BIN tables to ensure debit and credit classification is accurate as new Discover BIN ranges appear.

Will merchants still have routing choice on Capital One debit cards?

This is the key concern. The Durbin Amendment requires two unaffiliated network options on debit cards. When the issuer owns the network (as Capital One now does with Discover and PULSE), the independence of that second network is in question. Merchants should watch for changes to PINless enablement and fallback logic from Capital One over the coming months.

How will this affect interchange rates?

Discover debit interchange rates are generally not subject to the Durbin cap that applies to large-issuer Visa and Mastercard debit. Merchants should expect higher interchange on Capital One debit cards as volume migrates to Discover rails, particularly in card-not-present channels.

How can Harmonize help merchants track this migration?

Harmonize monitors your BIN-level data across all processors, automatically flagging when card type classifications shift. It can show you week-over-week changes in Discover debit volume on Capital One BINs, so you can see the migration as it happens and quantify its cost impact before your next processor negotiation.

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