--- title: "Crypto Custody Accounting for Banks (SAB 121 to SAB 122), Explained" description: "How the shift from SEC Staff Accounting Bulletin 121 to SAB 122 removed balance-sheet capital constraints, clearing the path for traditional financial institutions to offer crypto custody services." url: https://basisdesk.news/learn/sab-121-sab-122-crypto-custody-accounting published: 2026-11-05T22:30:31.649Z modified: 2026-11-05T22:30:31.649Z section: Regulation & Policy author: Basis Desk Newsroom (AI-generated, source-verified) sentiment: neutral tickers: [] tags: [custody, SAB 121, SAB 122, banks, SEC, accounting, capital requirements] license: Quote with attribution to Basis Desk (basisdesk.news). Not financial advice. --- # Crypto Custody Accounting for Banks (SAB 121 to SAB 122), Explained How the shift from SEC Staff Accounting Bulletin 121 to SAB 122 removed balance-sheet capital constraints, clearing the path for traditional financial institutions to offer crypto custody services. ## Key points - SAB 121 required companies to record safeguarded crypto assets as liabilities on their balance sheets. - On-balance-sheet treatment triggered punitive capital requirements for banks, making crypto custody economically unviable. - SAB 122 rescinded the liability requirement for custodians that meet strict bankruptcy-remoteness and security standards. - The change allows traditional banks to custody digital assets off-balance-sheet, similar to traditional financial securities. Traditional financial institutions generally hold client assets off their balance sheets, insulating the bank's own capital from the risks of the assets they safeguard. The introduction of Staff Accounting Bulletin 121 by the U.S. Securities and Exchange Commission disrupted this model for digital assets, forcing banks to record safeguarded cryptocurrencies as liabilities. The subsequent issuance of SAB 122 reversed this stance, realigning crypto custody with standard financial accounting and removing a significant capital barrier for banks. ## The Traditional Custody Model Banks custody trillions of dollars in equities, bonds, and other traditional financial instruments for clients. Under standard accounting practices, these assets are considered property of the client, not the bank. Consequently, custodial assets are held **off-balance-sheet** [1]. Because the assets do not appear on the bank's balance sheet as liabilities, the bank is not required to hold regulatory capital against them. The bank charges fees for the safeguarding service but does not assume the market risk of the underlying assets. This operational separation is a fundamental pillar of traditional financial custody. ## The Introduction of SAB 121 In March 2022, the SEC issued **Staff Accounting Bulletin 121** (SAB 121). The guidance directed entities that safeguard crypto assets for clients to present a liability on their balance sheets reflecting the obligation to safeguard those assets, along with a corresponding asset [1]. The SEC cited unique technological, legal, and regulatory risks associated with safeguarding crypto assets. The regulator argued that the cryptographic nature of digital assets, combined with a lack of legal precedent in bankruptcy courts regarding crypto custody, created significant potential liabilities for the custodian. By forcing the assets onto the balance sheet, the SEC aimed to ensure that public companies transparently disclosed these risks to investors. ## The Capital Requirement Catch While SAB 121 was explicitly an accounting bulletin, its interaction with banking regulations created a structural barrier for financial institutions. Bank capital rules, heavily influenced by the Basel Committee on Banking Supervision, require banks to maintain capital proportional to the assets and liabilities on their balance sheets [2]. When SAB 121 forced client crypto assets onto bank balance sheets as liabilities, it inadvertently triggered these **capital requirements**. A bank holding digital assets for a client had to reserve its own capital against the value of those assets, making the custody service economically unviable. ## A Worked Example: The Cost of SAB 121 Consider a hypothetical bank subject to a 10% supplementary leverage ratio (SLR) requirement. Assume the bank intends to custody $1 billion worth of Bitcoin for an institutional client. Under standard off-balance-sheet accounting, the bank records no new liability and owes no additional capital against the $1 billion. It simply collects its custody fee. Under SAB 121, the bank must record a $1 billion safeguarding liability on its balance sheet. To satisfy the 10% SLR requirement, the bank must allocate $100 million of its own Tier 1 capital to back this specific client activity. If the custody fee is 10 basis points ($1 million annually), the return on the $100 million of trapped capital is merely 1%. This capital drag makes the custody business highly inefficient compared to holding traditional securities. ## The Shift to SAB 122 The banking sector and legislative bodies pushed back heavily against SAB 121, arguing it kept highly regulated institutions out of the digital asset market. As bankruptcy courts established clearer precedents for crypto assets and custodians developed more robust security protocols, the initial justification for SAB 121 weakened. The issuance of SAB 122 rescinded the balance-sheet requirement of SAB 121, provided the custodian meets specific legal and operational criteria [1]. Custodians must demonstrate that client assets are bankruptcy-remote and that the institution utilizes enterprise-grade security infrastructure. By meeting these conditions, banks can return to standard off-balance-sheet accounting for crypto assets, eliminating the punitive capital charges. This shift allows banks to integrate digital assets into their existing custody frameworks. It also aligns with the broader regulatory evolution seen in rules governing investment advisers, as detailed in the [SEC Crypto Custody Rules for Advisers and Funds, Explained](https://basisdesk.news/learn/sec-crypto-custody). ## Common Misconceptions * **SAB 121 banned banks from crypto:** SAB 121 was not a ban. It was an accounting standard that made the business economics of crypto custody prohibitively expensive due to capital rules. * **SAB 122 removes all risk controls:** Returning to off-balance-sheet treatment does not exempt banks from risk management. Regulators still require strict operational security, regular audits, and clear legal agreements to ensure assets are genuinely bankruptcy-remote. * **Accounting rules dictate legal ownership:** Accounting presentation (on or off balance sheet) reflects the reporting of financial risk, but legal ownership is determined by the specific terms of the custodial contract and applicable commercial law. ## What to Watch The transition to SAB 122 alters the competitive landscape of digital asset custody. Traditional banks are expected to scale their crypto custody offerings, competing directly with crypto-native custodians. Market participants should monitor how the Office of the Comptroller of the Currency (OCC) and the Federal Reserve update their supervisory expectations for banks managing these operational risks, and whether the Basel Committee adjusts its prudential treatment of crypto asset exposures in response to changing national accounting standards. ## FAQ **What is an off-balance-sheet asset?** An asset held by a financial institution on behalf of a client where the client retains legal ownership. The institution does not record the asset as its own property or liability. **Why did SAB 121 require on-balance-sheet reporting?** The SEC cited the unique technological and legal risks of crypto assets, arguing that potential liabilities from loss or bankruptcy necessitated on-balance-sheet disclosure to protect investors. **How did SAB 121 affect bank capital rules?** By classifying custodial crypto as a liability, SAB 121 forced banks to apply their regulatory capital requirements against the value of the safeguarded assets, trapping bank capital. **What changed with SAB 122?** SAB 122 allowed custodians to revert to off-balance-sheet accounting for crypto assets, provided they can prove the assets are secure and legally protected in the event of bankruptcy. ## Sources 1. [Staff Accounting Bulletin No. 121](https://www.sec.gov/rules-regulations/staff-guidance/staff-accounting-bulletins/staff-accounting-bulletin-121) — U.S. Securities and Exchange Commission 2. [Prudential treatment of cryptoasset exposures](https://www.bis.org/publications/202212-standards-prudential-treatment-cryptoasset-exposures) — Bank for International Settlements --- Basis Desk Newsroom · AI-generated, source-verified · https://basisdesk.news/about/how-we-use-ai