Block, Inc. has applied to the Office of the Comptroller of the Currency (OCC) to charter Builders Bank & Trust, N.A., an uninsured national trust bank in Sioux Falls, South Dakota, that would custody bitcoin and settle stablecoins without taking deposits or making loans. The public volume of the application, dated September 4, 2026, puts the business plan and capital in confidential exhibits. Block’s own filings do show the economics being moved: its bitcoin line generated 45% of Cash App’s revenue last quarter but only 3% of its gross profit, and the charter would reach assets Block does not custody today.

What Builders Bank would do

Block announced the filing on September 8. The application lists four activities for the three-year de novo period: custody and safekeeping of “bitcoin and other digital assets”, execution of customer buy and sell orders on a riskless principal basis, deposit, withdrawal and transfer instructions, and “stablecoin settlement and transfer services”. Block will own 100% of the bank through two intermediate holding companies, capitalise it fully and pay its organisational costs. It will not seek Federal Deposit Insurance Corporation (FDIC) cover and says it falls outside the Community Reinvestment Act.

The legal wording is the tell. Builders Bank describes its business as “trust company operations or activities related thereto”. That tracks the OCC’s chartering rule, which since a final rule effective April 1, 2026 refers to “operations of a trust company and activities related thereto” instead of “fiduciary activities”. The OCC says the rule clarifies, without expanding its authority, that such banks may do non-fiduciary work, the footing for order execution and stablecoin settlement. The filing also asks the OCC to waive the director-residency rule: none of the five proposed directors lives within 100 miles of Sioux Falls.

The numbers Block did disclose

The application says Block facilitated about $10.7 billion of bitcoin transaction volume in fiscal 2025 and served roughly two million digital-asset monthly transacting actives on Cash App as of the second quarter of 2026. Block’s second-quarter 10-Q fills in the margin: bitcoin ecosystem revenue was $1.89 billion, down 13% from $2.17 billion a year earlier, against $1.82 billion of bitcoin costs. That leaves roughly $72.4 million of gross profit, a 3.8% margin. Block also held about 9,117 bitcoin of its own at June 30, carried at $533.9 million.

The same 10-Q states that “other than bitcoin, the Company does not hold or store any other types of crypto-assets for customers or trading partners.” Custody of other digital assets and stablecoin settlement would therefore be new business for Block, not just existing custody moved under one federal supervisor.

Where it joins the queue

The OCC conditionally approved five national trust charters on December 12, 2025, covering Circle’s First National Digital Currency Bank, Ripple, BitGo, Fidelity Digital Assets and Paxos. As we reported, only two of those five have opened. Full-service charters are priced very differently: the OCC set OpenReserve’s at $210 million of initial capital and a 12% leverage floor, and conditioned Revolut’s charter with retail forex fenced off.

The closest benchmark for Block’s hidden capital figure is the OCC’s latest crypto decision. The World Liberty Trust Company approval of August 14, 2026 requires at least $20 million of tier 1 capital, the greater of 50% of it or $10 million held in eligible liquid assets, a further 180 days of operating expenses in liquid assets, and opening within 18 months or the approval expires. Block would also run the new bank next to Square Financial Services, the FDIC-insured Utah industrial bank it has operated since March 2021.

“Building on Block’s experience in the digital asset space, our history with Square Financial Services, and the deep banking expertise of the team we’ve assembled, we believe Builders Bank is well positioned to support Block’s broader vision of economic empowerment,” said Lee Woolley, Digital Asset Strategy Lead at Block, who would chair the bank and serve as its President and CEO.

What happens next

Block gives no timeline, and the application is on the OCC’s standard rather than expedited track. A conditional approval would likely lock the business plan in place. The World Liberty letter requires 60 days’ notice and OCC non-objection before any significant change during the first three years of operation. The activity list has to survive now. If the OCC approves bitcoin custody but narrows the other digital asset and stablecoin lines, Builders Bank becomes a cheaper wrapper for a 3.8%-margin business. If all four activities survive, Block gets a federally supervised custodian it can sell to institutions as well as Cash App users. For advisers still seeking a qualified custodian, only the second outcome matters.

This article is informational analysis only and is not financial, investment, or trading advice. Cryptocurrencies are highly volatile and can lose substantial value rapidly. Past performance and historical patterns do not guarantee future results. Do your own research and consult a regulated financial adviser before making any investment decision.

Karthik Subramanian

Karthik Subramanian is a founder, writer, and technology consultant with nine years in the crypto ecosystem. He covers token economics, L1/L2 infrastructure, DeFi protocols, wallets/custody, and the bridge between crypto and forex—broker technology, liquidity, and macro drivers. Karthik’s writing focuses on clear, practical frameworks that help professionals evaluate new products and on-chain innovation alongside FX market realities.