Most teams treat the payment method list as a settings page. You toggle on cards, maybe a wallet or two, and move on. But in many markets the method a customer expects is not a card at all, and when it is missing the order does not convert at a discount. It does not convert.
We call this the abandonment tax: the share of ready-to-buy customers you lose purely because their preferred way to pay is absent from your checkout. It compounds quietly because it never shows up as a declined transaction. There is nothing to decline. The customer reaches the payment step, sees no method they trust, and leaves.
Why this sits inside the conversion stack
The authorization funnel (module two) only measures customers who picked a method and submitted. Local payment methods govern who reaches that funnel at all. A missing method is upstream of every routing and 3DS optimization you make later, so it caps the ceiling on everything downstream.
The baseline tells you why this matters. Baymard Institute's 2025 aggregate of published studies puts the average documented cart abandonment rate at 70.19 percent, and mobile is worse at roughly 80 percent. Not all of that is addressable. Around 43 percent of US shoppers abandon because they were "just browsing." The portion you can fix is the smaller slice tied to checkout friction, fees, and method availability, and method availability is the one many teams never measure.
What "local" actually means
A local payment method is the rail a given market defaults to, which is often not the global card networks. The pattern repeats across geographies with different mechanics.
In the Netherlands, iDEAL carries around 69 to 70 percent of online purchases, processing bank transfers directly from the customer's account. In Poland, BLIK reached roughly 65 to 70 percent of e-commerce share in early 2025, built on a six-digit code generated in the customer's banking app. In Brazil, Pix, the central bank's instant transfer scheme, hit about 42 percent of online sales in 2025, level with credit cards, and EBANX projects it past 45 percent by the end of 2026. In India, UPI processed over 228 billion transactions in 2025 and accounts for the large majority of digital retail payments.
The lesson is not "add Pix everywhere." It is that in each of these markets, shipping a card-only checkout means a majority of buyers either pay through a method they trust less or do not pay at all.
Sizing the tax before you build
Adding methods is not free, so you need a number before you commit. The estimate is straightforward and worth doing per market.
Take a market where your checkout is card-only. Estimate the share of buyers in that market who prefer a method you do not offer, then apply a recovery factor for the slice who will not substitute to a card. The recovery factor is the judgment call. A reasonable working range is 20 to 50 percent of the gap, depending on whether the alternative method is dominant or merely common.
Worked example
Suppose you do 1 million dollars a month in gross merchandise value in the Netherlands, card-only. iDEAL is the default for roughly 69 percent of Dutch online buyers. Many of those customers will still complete on a card, but a meaningful fraction abandon rather than switch.
Apply a conservative 25 percent recovery factor to the 69 percent who prefer iDEAL. That implies roughly 17 percent of attempted volume is at risk of walking away. Even if you halve that estimate to be safe, you are looking at an 8 to 9 percent uplift in completed orders from adding one method. Against a 1 million dollar baseline, that is 80,000 to 170,000 dollars a month. Run the same math per market and the priority order writes itself.
The point of the estimate is not precision. It is ranking. You will not add 30 methods at once, so the model tells you which three to add first.
The cost side: methods are not free to carry
The abandonment tax is real, but so is the operational drag of every method you switch on. Practitioners underweight this and end up with a bloated checkout that converts no better.
Each method adds settlement timing you have to reconcile (module nine), its own refund and chargeback or dispute flow, its own failure modes, and its own fee structure. Bank-transfer methods like iDEAL and Pix often clear faster and cost less than cards, which is a real margin benefit, but account-to-account rails can carry weaker buyer-side reversal protection that changes your fraud and refund posture.
There is also a UI cost. A payment page with 14 logos converts worse than one showing the three methods that market actually uses. This is why method selection should be conditional on detected country, not a global union of everything you support.
A simple rule for the method list
Show the dominant local method first, the card networks as the universal fallback, and at most one or two wallets or BNPL options that the data justifies. BNPL is a useful example of restraint: Klarna and the wider buy-now-pay-later category sit at roughly 5 to 6 percent of global e-commerce payment value, so it earns a place in some baskets and verticals but rarely deserves top billing.
Closing takeaway
Treat the payment method list as a P&L line, not a feature toggle. For each market, estimate the abandonment tax of the methods you are missing, rank by recoverable revenue, and add the smallest set that captures most of the gap. Then localize the display so each customer sees their default first and a short list behind it. The goal is not to support every method on earth. It is to never lose a ready buyer because the one rail they trust was absent from the page.