The stablecoin sandwich has emerged as one of the most persuasive conceptual frameworks in digital finance — a clean, intuitive model that explains how Bank for International Settlements-watched digital currencies can streamline the notoriously inefficient world of cross-border payments. Yet for all its elegance, the model as it currently stands contains a structural gap that its proponents have been slow to confront: the trust layer is absent, and that absence matters enormously.
The mechanics of the stablecoin sandwich are straightforward enough to have earned genuine traction among payments strategists, fintech architects, and banking technologists alike. A business begins with fiat currency held within the regulated financial system — a familiar, legally anchored starting point. That fiat is then converted into a stablecoin, which travels across a blockchain network as the middle layer of the sandwich. On the other side, the stablecoin is converted back into fiat currency, re-entering the regulated system at the destination. The blockchain transfer is fast, borderless, and largely indifferent to the correspondent banking relationships that make traditional cross-border settlements slow and expensive. On paper, it is a compelling architecture.
The problem, as analysts are increasingly acknowledging, is that the sandwich metaphor is misleading in one critical respect. A sandwich's structural integrity depends on what holds it together — and in the stablecoin model, the binding element between the regulated fiat endpoints and the permissionless blockchain middle is assumed rather than engineered. That assumption is the trust layer, and it is conspicuously missing from most real-world deployments of this model.
Trust in payment systems is not a soft concept. It is operational. It encompasses the legal enforceability of obligations between counterparties, the reliability of on- and off-ramp infrastructure, the compliance standing of the entities performing the stablecoin conversions, and the governance of the stablecoin itself. When a business converts fiat into a stablecoin to initiate a cross-border transfer, it is implicitly trusting that the stablecoin issuer maintains adequate reserves, that the issuer is subject to meaningful regulatory oversight, and that the recipient's off-ramp will honor the conversion at the anticipated rate and timeline. Each of those trust assumptions is currently either unverified or inconsistently regulated across jurisdictions.
This is not a theoretical concern. The cross-border payments corridor is a high-stakes environment. World Bank data has long highlighted the cost and opacity of remittance flows — precisely the market segment that stablecoin advocates cite as the primary use case for the sandwich model. Businesses and individuals routing payments through this architecture are exposed at the conversion points, which are also the points of maximum regulatory ambiguity. The regulated fiat system provides clear legal recourse. The blockchain layer provides cryptographic auditability. But the conversion interfaces — the on-ramps and off-ramps — sit in a zone where legal standing, consumer protection, and counterparty risk management remain underdeveloped in most markets.
Regulatory frameworks such as the Markets in Crypto-Assets Regulation in the European Union represent early attempts to address exactly this gap. By imposing reserve requirements, disclosure obligations, and authorization standards on stablecoin issuers, MiCA creates at least a partial trust infrastructure around the conversion points. Similar legislative efforts have advanced in the United States and the United Kingdom. But legislative intent and operational trust architecture are not the same thing, and the global patchwork of emerging stablecoin regulation means that a payment routed across jurisdictions may encounter a trust layer on one side of the sandwich and regulatory vacuum on the other.
The irony is that the stablecoin sandwich's most powerful selling point — its ability to bypass the friction of correspondent banking — is also the source of its trust deficit. Correspondent banking is slow and expensive, but it is also a network of deeply institutionalized trust relationships, backed by decades of bilateral agreements, anti-money laundering frameworks, and Know Your Customer protocols. When the stablecoin model routes around those relationships, it must replace them with something of equivalent trust value. Currently, it does not.
What This Means for the Payments Industry
The stablecoin sandwich will not reach its potential as a cross-border payments infrastructure until the trust layer becomes as deliberate and robust as the technical layers that bookend it. That means standardized reserve auditing for stablecoin issuers, enforceable legal frameworks at the conversion interfaces, interoperable compliance standards across corridors, and — critically — institutional accountability for the entities operating on- and off-ramps. The blockchain middle layer is, in a meaningful sense, the easiest part of the architecture to build. What financial institutions, regulators, and stablecoin issuers must now collectively engineer is the connective tissue of trust that makes the whole structure reliable enough to carry the weight of real commercial payments. Until they do, the sandwich remains a promise rather than a product.
Written by the editorial team — independent journalism powered by Codego Press.
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