BNPL Explained: How Buy Now, Pay Later Works — and Who Is Actually Winning

What BNPL Actually Is

Buy now, pay later is a form of short-term consumer credit offered at the point of purchase. Instead of paying the full price immediately — or reaching for a credit card — the consumer splits the payment into equal instalments spread over weeks. The canonical product is pay-in-3 or pay-in-4: three or four payments, each a few weeks apart, often with no stated interest rate. For a £120 jacket, that is three payments of £40, the first taken at checkout.

The framing — "interest-free," "no credit check," "just split it" — positions BNPL as a payment method rather than a credit product. That distinction matters commercially and legally, and it is precisely what regulators are now pulling apart. Someone pays for the credit. That someone is not the consumer, at least not up front.

Three Business Models That Have Been Conflated

"BNPL" has become a catch-all label applied to three structurally different products. Understanding which one you are looking at matters — they carry different economics, different default profiles, and different regulatory exposure.

Short-term interest-free instalments. The most common model. The consumer splits a purchase over 6–12 weeks with no interest charged. Klarna's "Pay in 3" and Afterpay's (Clearpay's in the UK) "Pay in 4" are the canonical examples. Revenue comes from the merchant, not the consumer — through a merchant discount rate typically between 3% and 6% of the transaction value. Late payment fees apply if a consumer misses an instalment, but the core product costs the consumer nothing if they pay on time. This is the product that captured the public imagination and drove BNPL's growth.

Longer-term instalment loans. 3–36 month terms, often with a stated APR. Affirm in the US operates this model, typically presenting it as a "buy now, pay over 12 months" option at checkout. Some offers are 0% promotional rate, subsidised by the merchant for specific campaigns; others carry interest. These products are substantively closer to a traditional personal loan than to a payment deferral — the consumer is borrowing money and, in many cases, paying interest. Affirm's economics look less like Klarna and more like a specialist consumer lender.

Revolving credit hybrids. Some BNPL products operate closer to a charge card with a refreshing credit limit. Zilch (UK) structured itself this way. Regulation tends to catch these as consumer credit products from the outset — the revolving structure is harder to argue away as a payment method. These are the rarest of the three models in the mainstream market.

How the Economics Work

Merchants pay BNPL providers 3–6% of the transaction value. For context, card interchange in the UK and EU is capped under the Interchange Fee Regulation — at 0.2% for consumer debit transactions and 0.3% for consumer credit transactions. But the total cost a merchant pays (the merchant service charge) is higher once acquirer fees and scheme fees are added, typically landing between 0.5% and 2% depending on card type and acquirer. BNPL at 3–6% is materially more expensive than accepting a regulated card, and the merchant accepts that cost because the conversion and basket-size benefits — for the categories where BNPL works — justify it.

Why do merchants accept it? Two reasons, both with data behind them. First, conversion: customers who cannot afford the full price at checkout complete the purchase when they can defer. Second, basket size: when consumers do not feel the full cost immediately, they buy more. The merchant effectively trades a higher transaction fee for higher revenue — and for many in fashion, electronics, and home goods, the maths works.

The BNPL provider makes money from three sources: the merchant discount rate (primary, for the short-term model); late payment fees charged to consumers who miss instalments; and, for interest-bearing longer products, interest income. Default risk sits entirely with the BNPL provider — the merchant is paid in full immediately, regardless of whether the consumer repays. This is structurally different from traditional trade credit, and it means the BNPL provider is underwriting consumer credit risk at scale while historically operating outside consumer credit regulation.

The unit economics are thin and sensitive to credit losses. When interest rates rose sharply in 2022–23, funding costs increased, late payments rose, and the sector's loss rates climbed. Laybuy — a New Zealand-founded BNPL provider operating in the UK — went into administration in 2024. It was a reminder that the model depends on low credit losses and cheap capital, and neither of those was guaranteed.

The Key Players

Klarna (Sweden) is the largest BNPL provider globally by consumer count — more than 150 million users and partnerships with hundreds of thousands of merchants at the time of writing. Founded in Stockholm in 2005, it was originally a payments processor before BNPL became the dominant product. Klarna's valuation reached approximately $46 billion in 2021, fell sharply to around $6.7 billion in its 2022 down-round, and it subsequently restructured aggressively — cutting headcount and refocusing on profitability. It went public in 2025. Its trajectory illustrates both the sector's appeal to growth investors and the underlying fragility when credit costs and funding costs shift.

Afterpay (Australia) built strong positions in Australia and the US with the pay-in-4 model. Block (formerly Square) acquired it in 2022 for approximately $29 billion — one of the largest fintech acquisitions on record. The integration into the Cash App ecosystem was Block's bet on connecting merchant-side and consumer-side finance. In the UK and Europe, Afterpay operates as Clearpay.

Affirm (US) pursues the longer-term instalment model and has built partnerships with major retailers — including a prominent integration with Shopify — for specific financing promotions. Its product mix means it looks more like a consumer lender than a payments overlay, and it is regulated accordingly in most markets. Affirm has been profitable on some metrics but its path to consistent net income has been long.

Paidy (Japan) operated a localised BNPL product suited to Japan's payment conventions — notably the prevalence of convenience store cash payment. PayPal acquired it in 2021 for approximately $2.7 billion, seeking to deepen its position in one of the world's largest e-commerce markets.

Several smaller players did not survive the rate cycle. Laybuy's administration in 2024 is the clearest UK example. Others consolidated or retreated from less profitable geographies. The sector has thinned considerably from its 2021 peak.

The Consumer Risk and the Credit File Problem

The "no credit check" claim requires careful unpacking. Most short-term BNPL products do perform some form of creditworthiness assessment — but typically a soft check, which does not leave a footprint on the consumer's credit file in the way a credit card application does. The problem is not the check itself; it is the invisibility of what follows.

Because BNPL commitments historically did not appear on credit files, a consumer could accumulate payment obligations across Klarna, Clearpay, Laybuy, Zilch, and a fifth provider simultaneously, with none of them able to see the others. A consumer earning £2,000 a month could have £600 in BNPL instalments due across the next three weeks with no single lender aware of the total exposure. This is the structural credit risk the sector has been running — and it is not hypothetical. The FCA's consumer research found meaningful proportions of BNPL users describing difficulty keeping track of multiple active obligations.

Credit bureaux have been working to integrate BNPL data. Experian, Equifax, and TransUnion in the UK have all announced BNPL data-sharing programmes, though uptake from providers has been uneven. Regulation is expected to accelerate this. Once BNPL obligations appear on credit files, they will affect affordability assessments for mortgages, car finance, and personal loans — a change that will concentrate minds among consumers who have treated BNPL as a cost-free convenience.

For AI underwriting systems that pull credit bureau data, the absence of BNPL has been a consistent blind spot. As that data arrives, affordability models will need updating — and some consumers who currently appear low-risk on a bureau pull will look materially different once their BNPL stack is visible.

Regulation: The Exemption That Is Closing

The rapid growth of short-term BNPL in the UK was enabled by a specific regulatory gap. Interest-free deferred-payment agreements repayable in no more than 12 instalments over no more than 12 months could rely on the exemption in Article 60F(2) of the Financial Services and Markets Act 2000 (Regulated Activities) Order 2001. Third-party BNPL lenders therefore operated outside the consumer-credit lending permissions that apply to conventional loans, although other consumer-protection law still applied.

That position changes on 15 July 2026. The FCA will begin regulating third-party Deferred Payment Credit: lenders will need authorisation or temporary permission, must carry out proportionate affordability checks, and customers will gain access to the Financial Ombudsman Service. Merchant-provided credit remains outside the new third-party-lender regime in many cases, so "all BNPL becomes regulated" would be an overstatement.

At EU level, the revised Consumer Credit Directive (Directive (EU) 2023/2225) broadens the regime to BNPL and credit below the former €200 threshold. Member states had to adopt implementing measures by 20 November 2025 and are to apply them from 20 November 2026. The direction across both markets is clear: third-party BNPL increasingly carries formal affordability, disclosure and redress obligations, but the exact perimeter still depends on who provides the credit and how the product is structured.

For the larger providers like Klarna, this is expensive but manageable — they have the compliance infrastructure and legal resource to absorb it. For smaller operators or newer entrants hoping to run lean on regulatory overhead, the cost structure changes materially.

The Open Banking Alternative

Several newer BNPL providers and some Klarna features use open banking affordability checks rather than credit bureau queries. By reading 90 days of bank statement data — with the consumer's consent — a lender can assess whether cash flow is actually sufficient to service the instalments, rather than relying on a bureau score that may be thin or stale. This is particularly valuable for younger consumers who have limited credit history but stable income.

Open banking-based checks have another advantage: they do not require a hard credit inquiry that leaves a footprint. As regulation requires creditworthiness assessments for BNPL, providers will need to choose between bureau queries (which affect credit scores) and open banking reads (which are consent-based and footprint-free). The latter is better for the consumer experience and arguably more accurate for affordability — which is why it is expected to become standard as the regulatory framework solidifies.

B2B BNPL: The Next Frontier

The same structural logic driving consumer BNPL applies in business-to-business trade. B2B buyers want to pay later; B2B sellers want cash now. Traditional trade credit terms (net-30, net-60) involve manual credit decisions, paper processes, and significant working capital strain on the seller. Automating that workflow — underwriting the buyer's creditworthiness programmatically, paying the supplier immediately, and collecting from the buyer over terms — is a sizeable opportunity.

Products like Resolve, Treyd, Billie, and Two — alongside embedded trade credit features from fintechs serving vertical SaaS platforms are applying BNPL logic to the business stack. The underwriting inputs differ — business bank accounts, Companies House filings, trade credit histories, sector-specific default rates — but the structural model is similar. This connects directly to the broader B2B embedded finance opportunity, where trade credit is being bundled into the platforms businesses already use rather than managed as a separate financing product.

B2B BNPL is earlier-stage than its consumer equivalent, and the addressable trade-credit market is large. Credit supplied to incorporated businesses generally sits outside consumer-credit rules, but the perimeter is not identical for every borrower: sole traders and some small partnerships can receive protections that do not apply to a limited company. Providers therefore need to classify the customer and agreement rather than treating every B2B transaction as automatically exempt.

Who Is Actually Winning

The honest answer is: the model is under pressure, the regulatory moat that enabled fast growth is eroding, and the competitive dynamics favour the largest players who can absorb compliance costs, achieve scale in merchant partnerships, and manage credit risk with better data.

Klarna and Afterpay/Block have the scale and brand recognition to survive the regulatory transition and absorb higher compliance costs. Both have also been moving upmarket — offering banking-adjacent products, loyalty programmes, and shopping apps that reduce dependence on the pure transaction fee. The long-term play is consumer relationship, not pure payment processing.

Mid-size and smaller players face a harder path. Regulation raises the minimum viable compliance cost; credit bureau integration will surface the riskiest consumer segments more clearly; and rising funding costs have already proved lethal for thinner-margin operators. The sector will consolidate further.

The merchants benefit in the near term — conversion uplift is real, and the cost comes off gross margin rather than headline revenue. But as BNPL becomes regulated consumer credit, the compliance and liability landscape for merchants embedding BNPL in checkout flows will also shift.

Consumers are in a more ambiguous position. BNPL has provided genuine access to short-term liquidity — particularly for consumers without credit cards — and for people who pay on time, it has been genuinely cost-free. The risk is that easy access and low friction have encouraged spending beyond means, particularly among younger consumers who are less experienced with managing debt. Regulation that requires proper affordability checks and makes BNPL visible on credit files is, on balance, better for consumers — even if the process of getting there reduces access for some.

Sources and methodology: This article draws on the FCA's Deferred Payment Credit rules and consumer guidance; the Financial Services and Markets Act 2000 (Regulated Activities) Order 2001 as amended; Directive (EU) 2023/2225; UK government BNPL consultation documents; publicly available filings and investor communications from named providers; and reporting on Laybuy's 2024 administration. Named company capabilities and valuations reflect publicly available information at the time of writing. No proprietary data is cited.