Why smart applications are providing crypto cards to their users

In March 2024, crypto payments writer tzedonn shared what might happen if he opted to use a crypto card to buy a cup of coffee for 3 British pounds.

In his article, he lays out the exact flow the asset would take to get from chain to card to coffee. 

Starting with USDC on Base he’d move funds to the Gnosis Chain, home of his Gnosis Pay crypto card, and then he would swap it for GBPe, a British pound stablecoin, to fund the card. Once the card was funded, he would then tap his card to purchase.

Underneath the hood, Gnosis Pay would check the balance and move the GBPe from the user’s smart-contract wallet to its payment partner. The merchant would receive pounds, the payment would clear, and tzedonn would buy his coffee.

That payment flow was an early example of how stablecoins and smart-contract wallets can work behind a familiar card experience, turning an onchain balance into an everyday purchase.

Today in 2026, crypto card spending has grown into a measurable onchain economy. People aren’t just buying cups of coffee. They’re using crypto cards for everyday purchases, travel, subscriptions, and other major expenses.

Crypto card monthly volume has risen throughout the years from about $100 million in early 2023 to $1.5 billion by late 2025, a 15x increase and an annualized run rate of roughly $18 billion.

This article ranks the best chains for crypto cards based on real card volume, while examining how issuers influence where transactions ultimately settle. It also explains how Turnkey secures these transactions at the signing layer through key management and programmable policies.

Why applications should provide crypto cards to their users

‍BVNK's 2026 research found that 71% of users would use a stablecoin-linked debit card if their bank or fintech app offered one, and 77% would open a stablecoin wallet on the same prompt. 

Crypto cards today ride Visa and Mastercard's existing rails, so a user can spend at the tens of millions of merchants that already accept those networks, with no merchant needing to touch crypto and the stablecoin-to-fiat conversion happening once, at authorization. 

And launching a crypto card is no longer a multi-year bank project: issuer-processors like Rain and Bridge now handle the licensing, settlement, and network relationships, and are embedding card issuing directly into developer APIs, so an app can go live in weeks. 

Choosing an issuer for your crypto card program

Behind every consumer card brand sits an issuer-processor that connects a stablecoin balance to Visa or Mastercard, and this layer decides settlement speed, which stablecoins and chains a program can use, and how fast a partner can launch. Today, there are two major players.

Rain

Rain is a stablecoin-native issuance platform and a Visa Principal Member, which is rare for a non-bank. This status allows Rain to issue cards directly without sponsor banks while running proprietary settlement. 

When a Rain card is used, the stablecoin sits in a smart contract as collateral, Rain underwrites a credit line against it, and the merchant is paid in fiat through Visa. 

Critically, Rain settles all Visa card volume in USDC daily, with Visa redeeming from Circle, so authorization and settlement run onchain.

Bridge

Bridge is a stablecoin infrastructure platform. Its jointly issued Visa card program launched in 2025 in Latin America and, per Visa's own announcement, was live in 18 countries with plans to reach more than 100 by the end of 2026. 

Card transactions can settle onchain through Bridge's partnership with Lead Bank, which settles on Solana in Visa's pilot, and Bridge powers cards for wallets including Phantom and MetaMask. 

For an app that wants the broadest country coverage out of the box, its expanding Visa footprint is the draw.

Where your users hold stablecoins: 6 chains, ranked

The chains below are where users hold stablecoins and fund their cards, not where the card issuer settles with Visa. For example, Rain settles in USDC, while Bridge settles through Lead Bank on Solana.

The issuer manages that part of the process, but users are more affected by the chain they use to add or withdraw funds. It determines fees and whether they can spend the stablecoins they already hold without first moving them to another network.

The best chain is therefore not always the fastest. It is the one where users already hold stablecoins and can move them at a low cost. The rankings below show where most crypto card activity currently takes place.

TRON leads on liquidity, not novelty

TRON carries more card volume than any other chain, roughly 39% of cumulative deposits and more than a third of monthly spend. The reason is liquidity: the network hosts more USDT than any other chain, around $86 billion and processes about two-thirds of USDT remittances. 

TRON is often chosen for its speed and low cost. Transactions are added to the blockchain about every three seconds, and fees typically stay below one dollar.

There is a tradeoff, though. TRON relies on 27 elected super representatives to validate transactions and govern the network, concentrating control among a relatively small group of operators. Its crypto card activity is also heavily dependent on a single asset, USDT. 

That concentration gives TRON a powerful liquidity moat because users, merchants, and payment providers already have deep access to USDT across the network. 

At the same time, it creates risk. Any disruption involving USDT, its issuer, or TRON’s validator set could affect a large share of the chain’s card activity at once.

BNB Smart Chain is the strongest EVM alternative

BNB Smart Chain ranks second, handling about 15% of volume. It now adds transactions to the blockchain in less than half a second and confirms them as final in about one second, with typical fees well below one cent.

BNB Chain now accounts for about 32% of all peer-to-peer stablecoin transactions across chains, moving well over $100 billion in a single month. For an EVM-based app that wants reach without Ethereum's cost, it is the obvious candidate.

Like TRON, BNB Smart Chain trades some decentralization for speed. A relatively small group of 40 validators processes and confirms transactions on the network.

Ethereum offers deep liquidity but comes with higher transaction costs

Ethereum sits around 11% of card volume. It holds the largest single-chain stablecoin base, around $153 billion, close to half of all onchain dollars. 

The tradeoff is cost, and it directly shapes where applications build. Although Ethereum mainnet fees have improved, they remain higher than on many competing networks. 

As a result, applications rarely process high volumes of card transactions directly on Ethereum. Instead, they use Ethereum layer 2 networks such as Base, Arbitrum, and Optimism, which offer lower fees while preserving access to Ethereum’s liquidity and ecosystem.

Solana is the USDC counterpart to TRON

Solana handles roughly 8% to 12% of crypto card volume. Transactions begin confirming in less than half a second, fees cost a fraction of a cent, and Visa uses Solana as its primary network for US stablecoin settlement.

On liquidity, USDC transfer volume on Solana surpassed Ethereum in late December 2025, and by April 2026 Solana captured 32.6% of weekly adjusted stablecoin transfer volume, ahead of Ethereum, TRON, and Base. 

Optimism and Arbitrum are the general-purpose L2 tier

Optimism is a low-cost Ethereum layer 2 network used for stablecoin payments. It became a major chain for card volume in April 2026, when ether.fi completed its migration from Scroll to OP Mainnet, moving roughly 70,000 active cards, 300,000 accounts, and $220 million in total value locked in a three-day cutover with no downtime. 

Its main drawback is that direct withdrawals to Ethereum can take up to seven days, although third-party services can make them faster.

Arbitrum rounds out the tier at about 3% of deposits, holding roughly $4 billion in stablecoins, among the deepest of any layer 2.

Alongside Base and Optimism, it supports stablecoin transfers for less than $0.30, with transactions confirmed almost immediately. These networks give builders access to Ethereum’s security with lower fees and faster transactions.

What this means for builders creating their own cards

For teams building a crypto card program, two conclusions follow.

First, card programs need to be multichain because users already hold stablecoins across different networks. USDT liquidity is concentrated on TRON, while USDC is widely used across Solana, Ethereum, and its layer 2s. Supporting only one chain limits the customers a program can serve or forces users to bridge and swap before spending, adding cost and friction.

Second, the hardest problems sit at the infrastructure layer. Card providers need to create wallets across chains, secure users’ private keys, and enforce spending controls. Getting this layer right determines whether a card program can operate safely and scale, regardless of which chains carry the most volume.

How Turnkey secures crypto card transactions

Turnkey helps applications solve these infrastructure challenges through a single API integration. Builders can create wallets, manage transaction signing, and enforce spending controls across chains without building separate key management systems for each network.

Rather than tying applications to a specific chain or wallet model, Turnkey gives card providers a consistent security layer across networks, whether users hold USDT on TRON, USDC on Solana, or stablecoins across Ethereum and its layer 2s.

Private keys are generated and used inside secure enclaves, where they remain inaccessible to the application, user’s device, and Turnkey. Only the completed signature leaves the enclave.

Turnkey’s policy engine also runs in a secure enclave environment. Before signing, it checks who approved the transaction, where funds are going, how much a given transaction can move, and whether additional approval is required.

Because these controls operate separately from the application’s backend, compromising its servers does not expose keys or provide unrestricted signing access. Requests outside the approved policy are denied.

ether.fi Cash demonstrates how this model works in practice. Turnkey creates a non-custodial wallet for each member and assigns it to that member’s vault. 

Neither ether.fi nor Turnkey can access the underlying private key. This allows ether.fi Cash to provide a non-custodial card experience while applying controls when onchain transactions are authorized.

The model is straightforward: choose the chains and card issuer that best match where customers hold and spend their stablecoins, then secure the wallets and transaction controls at the signing layer. 

The chains and issuer determine how value moves. Turnkey ensures it moves only when an authorized request satisfies the application’s policies.

Build secure crypto card experiences with Turnkey

Crypto cards connect onchain assets to familiar payment rails, but building one requires more than choosing a fast or inexpensive blockchain. Teams need an issuer that fits their market, access to the chains where users already hold stablecoins, and wallet infrastructure that keeps keys secure while enforcing spending rules.

Turnkey gives builders the wallet infrastructure to create non-custodial card experiences across chains, secure private keys inside enclaves, and enforce user-defined policies at the signing layer.

Get started with Turnkey today. 

‍