Debit routing can offer a significant cost saving opportunity for merchants, as demonstrated in the piece “Why Routing Matters”, but execution is far from simple. While regulation opens new opportunities, there are several complexities merchants must navigate before reaching true routing optimization. Without a comprehensive strategy in place, even merchants with the most sophisticated tools could be routing around solvable problems.

CMSPI is out to market with billions of debit transactions every day, tackling untapped performance and savings improvements. This article explores four of the most impactful factors that could be eroding your routing choice today.

1. BIN Issuance Shifts Can Wipe Out Routing Savings

BINs, or the first 6 to 8 digits of a card, allow merchants to identify the set of networks available for routing for a given transaction. Changes in issuer partnerships with networks or modifications to product offerings can change the available networks on cards, resulting in potential outcomes costing retailers millions, such as missed volume requirements, reduced return on routing strategies, and cost increases for previously optimal routing strategies.

Over the past five years, issuers have periodically adjusted BIN ranges, reflecting changes in strategic partnerships, mergers and acquisitions, and regulatory developments (Figure 1). From 2019 to 2022, several large issuers underwent significant BIN restructuring due to processor-network relationship shifts, resulting in network availability shifts on 9.8% of transactions in 2022 alone.¹ The Federal Reserve clarification in 2023 further reshaped issuance patterns, driving issuers to update card-not-present (CNP) PINless network enablement which resulted in a record-breaking 16.1% shift in network badging.² In 2024, we observed how just a handful of issuers could alter routing strategies for a significant share of transactions in the U.S.: two large U.S issuers removed a globally-owned domestic network from their cards, shifting a significant share of transactions across the U.S. within just a six-week period.³ 

Looking ahead, 2025 and 2026 will add a new layer of complexity as Capital One is expected to consolidate its debit portfolio under a three-party network structure. As Capital One migrates portions of its debit portfolio to Discover and its domestic debit arm, PULSE, merchants could see new BIN ranges which shift routing eligibility from Mastercard, which is currently badged on many Capital One debit cards.⁵ Meanwhile, PULSE badging by other issuers could contract as the ownership of PULSE shifts to Capital One, potentially creating new issuance opportunities for other regional networks.⁶ To learn more about how this merger could reshape routing dynamics and what merchants should look out for, read our deep-dive here: “Capital One’s Discover Acquisition: A Payments Industry Game-Changer”.

2. CNP PINless Networks Can Also Shift Without Warning

BIN issuance shifts don’t just impact PIN debit transactions – merchants are also seeing changes in CNP PINless network badging, a trend that adds yet another dimension to routing complexity. ​In contrast to the PIN environment, CNP PINless-enabled cards often have only one alternative active PINless-capable network (Figure 2), meaning there is limited redundancy if that network is changed. As a result, even minor shifts can have disproportionately large impacts on PINless routing options.

Merchants must routinely monitor their priority routing strategies, as a single BIN issuance shift can erode significant savings if not adequately accounted for. Between January and July of 2025, 4% of CNP transactions saw the available PINless networks on the card change, either as the result of new networks being added, network swaps, or networks being removed from the cards according to CMSPI estimates. These changes can happen over a month, week, or even day – in Figure 3 we show that anywhere from 0.25% to 1.3% of CNP transactions in a given month may see the available networks shift (Figure 3).

3. Emerging Technology Can Obscure Network Availability

Other factors like network tokens, virtual cards, and digital wallets, which may mask the original BIN and subsequent network availability, can affect how debit transactions are routed, and merchants need to consistently review their BIN tables and payment method mix to identify any shifts in network availability.

4. Partner Capabilities May Affect Routable Volume

Even if these factors are accounted for, some partners may not have the capability to support full routing choice across all channels and networks. With a diversity of capabilities and certifications, it’s incumbent on merchants to work closely with their partners to ensure routing logic can account for complex routing arrangements and is being maintained properly. Table 1 is an example of variation in capabilities and certifications across providers reflecting CMSPI observed market trends.

Saving Requires Strategy

Debit routing remains a highly effective way of optimizing payments performance for merchants, offering huge potential savings. Achieving routing optimization, however, is not a ‘one size fits all’ process. From regulation and issuer behavior to product innovation and partner technology, each piece of the puzzle necessitates merchants’ active monitoring of their routing strategy.

Whether you’re new to debit routing or have a pre-existing routing optimization solution, connect with our experts to get the latest data on PINless enablement, market insights, and emerging trends in routing optimization.