From Swipe to Zap: How Square’s 0% Bitcoin Button Could Rewrite Everyday Payments

Square’s new Bitcoin button has quietly dropped into the payments world, but the impact is anything but quiet. Overnight, about four million US merchants using Square suddenly gained access to a 0% fee Bitcoin checkout option that lets customers pay over the Lightning Network with instant settlement and no processing costs until 2027. After that, the fee becomes a flat 1%, still well below the typical 1.5–3% card fees most businesses are used to swallowing. The whole thing works through Square and Cash App, so instead of feeling like some quirky crypto experiment, it behaves almost exactly like tap-to-pay except it runs on Bitcoin.

The core experience is simple. A seller selects Bitcoin on the Square terminal, a Lightning invoice pops up as a QR code, and the customer scans it with Cash App or another Lightning wallet. The payment settles within seconds, and merchants can choose to keep the Bitcoin or instantly convert it into US dollars. There’s a $600 cap per transaction, which fits nearly all everyday in-store purchases, from coffee to books to haircuts. While the surface looks uncomplicated, this rollout is actually one of the biggest real-world tests Lightning has ever seen, turning millions of potential endpoints into a direct payment path through Block’s network.

This surprise move reflects years of Bitcoin obsession inside Block. Cash App already handles billions in Bitcoin trading per year, and Block operates one of the most active public Lightning nodes by capacity. The company has slowly built the infrastructure piece by piece, and now it’s flipping the switch for mainstream users. The 0% fee period is a huge incentive for merchants, especially those living on thin margins. Even after 2027, a 1% fee still undercuts standard card costs. More importantly, Bitcoin payments remove chargebacks entirely, giving small businesses a clean way to avoid one of the most frustrating parts of card processing.

Of course, the setup isn’t free in the deeper layers. Instead of making money on card fees, Block earns on Bitcoin spreads and conversions inside its ecosystem. When customers buy Bitcoin through Cash App, spend it at checkout, or when merchants convert BTC back to USD, Block captures revenue on the exchange like flow behind the scenes. For the merchant, none of this matters they simply see lower fees and fast settlement. For Block, it creates a closed-loop river of Bitcoin liquidity moving between buyers, sellers, and its own treasury systems.

Lightning itself gets pushed into a new era with this rollout. Suddenly, everyday commerce can move through Block’s channels, creating a hub-like structure that increases convenience but concentrates routing power. It’s a trade-off: better user experience but greater centralization risk. Still, for most people, Bitcoin becoming easy enough to use without thinking about nodes or channels is exactly what adoption requires. The $600 limit also helps keep Lightning traffic manageable while steering usage toward realistic, daily-spending scenarios rather than large, risky transactions.