Volume III · Bitcoin · Money Research

06 — What Legal Tender Requires, and What Bitcoin Still Lacks

What "legal tender" actually means

“Legal tender” is a jurisdiction-specific legal label, not proof that an asset is widely used as money. Acceptance of an offered payment, discharge of a debt, tax payment, pricing and the economy's unit of account are different questions; one jurisdiction's rules do not define them for every other country. El Salvador's 2021 Bitcoin Law required merchant acceptance alongside the U.S. dollar. Decree 199, adopted 29 January 2025 and effective 90 days after publication on 30 January, amended rather than repealed that law. Its article 1 still uses “curso legal,” but private acceptance became voluntary, the authorization to pay taxes in Bitcoin was repealed, and public-sector participation was restricted. The IMF describes the change as removing the essential features of legal tender; that is a description of the law's effect, not a claim that its literal label vanished. Decree 199, arts. 1–8; IMF Country Report 25/58, para. 27 n.18.

A country considering Bitcoin for payment law, public assets or native denomination would need to specify the relevant statute, tax/debt rules, public mandate, banking treatment and actual use. The IMF's 2023 policy paper offers member guidance, not an identical statutory checklist for every country. “Bitcoin fails most of it” requires country and use-specific evidence and is withheld as a universal current verdict. IMF 2023 policy paper, paras. 33–39.

The legal architecture

Monetary law. Currency, tender, debt-discharge and court-valuation rules depend on the jurisdiction and may require different legislative acts. El Salvador's Decree 199 amended merchant acceptance and tax authority while retaining “curso legal” wording; it does not prove that every dollarised or currency-union country has the same seigniorage or central-bank constraints. The earlier “only two experiments” and “failed at once” causal explanation is withheld until each domestic and union statute is reviewed. El Salvador, Decree 199, arts. 1–8.

Monetary-union treaties. A member's ability to alter currency or tender rules depends on the exact union treaty, reserved powers and domestic law. The Central African Republic and euro-area examples need their own primary treaty and court locators before this chapter can claim that every union member is categorically unable to act alone or that all tender restrictions are identical.

Central-bank reserve statutes. A reserve mandate depends on the institution's governing law, asset categories and board authority. The CNB described its digital-asset test as outside international reserves; that limited experiment does not itself authorize a reserve allocation. The earlier Powell/Japan quotations, universal legislative-requirement claim and prediction of government reversal are withheld until exact statutory sections and transcripts are reviewed. CNB test-portfolio release.

IMF conditions. The IMF's 2023 policy guidance recommends against official-currency/legal-tender status for crypto assets and against central-bank holdings of unbacked crypto as official reserves. Programme conditionality, tax/payment requirements and public-asset limits must be read in the country's own agreement and implementation documents; guidance alone does not impose El Salvador's conditions on Pakistan, Argentina or every surveillance case. IMF 2023 policy paper, paras. 33–39; IMF El Salvador CR 25/58, para. 27 n.18.

The financial architecture

Bank regulation. The Basel Committee's revised cryptoasset standard has an international implementation date of 1 January 2026, not 2025; actual application depends on each jurisdiction's rules. Under the standard, an unbacked exposure such as bitcoin normally falls in Group 2b, with a 1,250% risk weight. The Group 2 exposure threshold is 1% of Tier 1 capital, with more severe treatment if it exceeds 2%; these are not a simple blanket ban on bank holdings. Custody, payments and balance-sheet exposure must also be distinguished. Basel Committee, SCO60, especially 60.83–60.86 and 60.116–60.119.

Accounting. FASB ASU 2023-08 requires fair-value measurement for qualifying crypto assets in reporting periods beginning after 15 December 2024; it does not mean every company could first hold Bitcoin in 2025. IFRS and public-sector classification depend on applicable standard and entity. The former universal “other assets” booking and discretionary-marking claims are withheld without named public accounts and accounting locators. FASB ASU 2023-08, scope and effective date.

Tax. Tax denomination, gain recognition and payment reporting follow domestic law. In the U.S., the IRS classifies convertible virtual currency as property for federal income-tax purposes; transaction-specific basis, gain and reporting rules should be checked rather than treating every Bitcoin payment as the same taxable dollar disposal. El Salvador's amended statute removed its earlier authorization for Bitcoin tax payments. The former India rate/effect claim and U.S. de-minimis legislative status remain withheld until current enacted texts are attached. Fiat-denominated taxes do not prove that every private wage, debt or price is denominated in fiat. IRS Notice 2014-21, Q&A 1–3; El Salvador, Decree 199, art. 7.

Anti-money-laundering rules. FATF Recommendation 16 and its virtual-asset guidance concern information-sharing duties for covered intermediaries; actual domestic transposition, exemptions and enforcement vary. The former 99-jurisdiction count, automatic grey-listing consequence and claim that every Bitcoin-denominated economy needs one banking form are withheld until FATF and local implementation records are checked. FATF virtual-assets guidance, Recommendation 16 discussion.

The economic requirements

Price stability. A wage, rent or loan denominated in Bitcoin would expose its parties to purchasing-power changes unless contracts or hedges allocate that risk. One SEC filing valued Bitcoin at $87,549.41 on 31 December 2025 and $58,745.18 on 30 June 2026 using the same principal-market convention; that is a six-month asset-price window, not a matched annualised-volatility test or proof native contracts cannot work. The former 10% threshold and 2025 low-year figure are analyst choices or unaccepted measures, not a structural law. Grayscale Bitcoin Mini Trust ETF, June 2026 Form 10-Q, note 3.

Elasticity and a lender of last resort. Bitcoin's permitted base issuance does not expand on discretionary demand. Deposits and redeemable claims around it could expand or contract, and an emergency lender's options would depend on law, reserves and conversion promises. The 2022 crypto-intermediary failures are not a national Bitcoin-credit observation or proof that every backstop is impossible. Weber, 2016, §§2–4; Bank of England, *Money creation in the modern economy*.

Payment infrastructure. Wallet availability, liquidity, merchant tools, recourse and end-to-end cost would matter under any Bitcoin-payment policy. Chivo download/repeat-use and Bhutan merchant-customer counts need original programme or field-study dates and populations before being used as national outcomes. Lightning public-channel capacity is not daily payment value or a test of whether a country's commerce is covered; the former 4,900-BTC figure is withheld as an unaccepted live observation. Lightning Labs, channel-liquidity guide.

A population willing to use it. Use cannot be established from a law or a wallet download alone. Purchases, native denomination, Bitcoin transfers and dollar-stablecoin flows need separate population and transaction measures. The Salvadoran, Bhutanese and country-ranking claims formerly bundled here remain source-open; Nigeria's covered CEX fiat-purchase share and IMF-estimated crypto-inflow share are distinct channels, not a ranking of which asset “mostly” served citizens. Chainalysis 2025 Nigeria section; IMF Nigeria CR 26/125, annex VII.

The political requirements

A fiscal settlement. Issuer revenue, central-bank balance sheets, deficits and borrowing differ by arrangement. A Bitcoin-native standard would alter the state's ability to issue the base asset, but does not imply balanced budgets or prove that every major economy faces the same choice. The Minneapolis Fed working paper models a conditional permanent-primary-deficit case; it is not a Federal Reserve policy recommendation or a dated 2026 public-debt observation. The earlier $39 trillion and “no government” assertions are withheld here. Minneapolis Fed WP 807, abstract.

Consensus that survives an election. A reserve or native-denomination policy needs authority and durability under its governing law. The U.S. Strategic Bitcoin Reserve is an executive direction concerning eligible finally forfeited Treasury Bitcoin, not a statute requiring purchases or national pricing in Bitcoin. Other referendum, bill and central-bank positions need country-specific records; the claim that every reserve attempt went through a legislature or referendum is withheld. U.S. reserve order, §§2–3.

What is still missing, in order of difficulty

Tax, accounting and acceptance rules can be changed by statute, as El Salvador demonstrated in both 2021 and 2025. Payment infrastructure and custody can be built, but law alone cannot produce price stability, an elastic credit system or a population that chooses to use Bitcoin. The 2025 Salvadoran statute still calls it “curso legal” while removing mandatory private acceptance and tax-payment authority, so a claim that no country uses the label would confuse terminology with practical legal effect. Decree 199; IMF Country Report 25/58, para. 27 n.18.

Key takeaways

The legal effect of Bitcoin adoption depends on the jurisdiction's rules for debts, taxes, pricing, public institutions and private acceptance; none follows automatically from a “legal tender” label. El Salvador's 2025 amendment kept “curso legal” in the statute while making private acceptance voluntary and removing tax-payment authority. It did not make Bitcoin the country's general unit of account, and it did not repeal the entire law. A broader monetary role would also depend on price stability, payment access, custody, credit arrangements and actual public use—questions that legislation alone cannot answer. Decree 199, arts. 1–8.