EU rules require stablecoins issued by electronic-money institutions to keep at least 30% of their reserves in commercial-bank deposits, rising to 60% for significant tokens. Britain's policy for systemic sterling stablecoin reserves excludes those deposits from coin backing. European central banks now want to remove the EU requirement, bringing the two approaches closer on the risk banks pose to stablecoin reserves.

Reuters reported on Sept. 22 that the European System of Central Banks, comprising the European Central Bank and EU national central banks, recommended replacing the compulsory bank-deposit share under the Markets in Crypto-Assets regulation with minimum reserve percentages in assets maturing within one and five working days. The proposal would change where issuers must keep redemption money; MiCA's existing requirements remain in force.

The same day marks the Bank of England's consultation deadline for its draft systemic stablecoin Code of Practice. Its June policy already ruled out commercial-bank backing because of financial, operational and contagion risks. The Bank intends to finalize the code by the end of 2026.

The regimes cover different types of issuer and are at different stages of implementation. Yet the recommendation points toward a shared concern: putting stablecoin reserves in banks can connect two sources of financial stress.

MiCA's deposit requirements make commercial banks part of the mechanism for meeting redemptions. Cash that backs a token also becomes funding for the bank where the issuer holds it, tying the coin's ability to repay holders to that bank's ability to return the money.

The problem runs in both directions. In a June speech , the ECB explained that bank failure can damage confidence in the quality and availability of stablecoin reserves. USDC's March 2023 loss of its peg, when some backing sat at failing Silicon Valley Bank, illustrated that exposure.

Reverse the sequence and the risk moves into the banking system. If holders rush to redeem a stablecoin, the issuer may withdraw large deposits from its banks to repay them. Money held as a reserve for token holders becomes funding that a bank can lose abruptly.

The reserve can therefore transmit a run as well as help meet one. An issuer's attempt to honor its promise to token holders can force its banks to replace funding at precisely the moment confidence is weakening.