Bank of England stablecoin rethink tests UK payments strategy

The Bank of England’s rulebook for sterling systemic stablecoins is being rewritten in all but name. Two numbers tipped it: a £20,000 cap on what any individual could hold, and a reserve formula that would park 40 per cent of backing assets at the central bank — unremunerated — while allowing 60 per cent in short-dated UK government debt. The original idea was to slow deposit flight from commercial banks into private digital money. Read another way, those numbers also told issuers what the UK thought it could charge for a licence to operate at scale.

Whether one consultation lands softer than the first draft is now the smaller question. The bigger one is whether the UK wants payment stablecoins to develop inside its regulatory walls or mostly outside them. The Bank is still trying to protect bank funding and preserve confidence in money. But it also has to decide how much friction it can impose before the most commercially serious issuers conclude London is a market to reach from offshore rather than a place to anchor a business.

Under the original proposal, retail users would be limited to £20,000 in systemic stablecoin holdings, while businesses would face a £10 million cap, according to the consultation paper. The same document said only 60 per cent of backing assets could sit in short-term UK government debt, with the other 40 per cent parked at the Bank of England and earning nothing. For firms judged systemic at launch, the paper also sketched a transitional regime in which as much as 95 per cent of backing assets would be held at the central bank. On paper, the arrangement reads as prudential. For an issuer, it also operates as a price signal.

Sarah Breeden, the Bank’s deputy governor for financial stability, told Reuters in March that policymakers were “genuinely open” to revising the rules. A later CoinDesk report quoted her describing parts of the package as “overly conservative.” Breeden’s language suggests the Bank now sees the original framework as a live market-structure problem, not a finished safety template. Industry pushed back directly. Katie Haries, Coinbase’s head of policy for Europe, said “a cap on stablecoin holdings is a cap on innovation.” The line is self-interested, but it lands. Hard caps and low-yield reserve mandates do not just restrain growth after a product succeeds — they shape whether an issuer launches in that market at all.

Why the reserve mix matters

Stablecoin regulation is often framed as a backing-quality question. The harder question is earnings capacity and liquidity management. A reserve pool that must keep 40 per cent in non-remunerated central-bank deposits is safer in one obvious sense. It also forfeits the income that normally pays for compliance, redemption operations, distribution and fraud controls. For a payment token, where margins are thinner than in speculative trading, that matters more. If the objective is to attract well-capitalised, closely supervised issuers, the reserve formula cannot ignore the economics of being supervised.

A Warwick Business School paper argued the live issue is not solvency alone but the liquidity mechanics around large redemptions and the credit strains that appear when reserves must be mobilised quickly. The Bank’s framework tries to ensure a payment stablecoin can absorb stress without becoming a run accelerant. But a regime fixated on static reserve composition can miss the operational side entirely: who redeems, how fast cash moves, what happens when settlement demand spikes, and whether the issuer has enough commercial room to build resilient plumbing before it is systemic.

Legal analysis from Bratby Law flags a second tension. The UK is designing what amounts to a dual-track system — one regime for systemic sterling stablecoins, another for firms that stay below the threshold. That architecture creates its own incentive problem. Issuers may try to stay just outside the tightest perimeter, fragment activity across products, or locate issuance in jurisdictions where reserve rules are less punitive while still serving UK users. None of those outcomes improves oversight. They just relocate the fight.

The real policy trade-off

Strip away the crypto framing and the debate is about where regulators want the costs of safety to sit. A strict cap on holdings protects banks from fast deposit substitution, but it also keeps stablecoins from becoming widely useful in ordinary payments. A high share of non-interest-bearing reserves gives the central bank more immediate control, but it makes the regulated model less attractive than versions built abroad or kept below the systemic bucket. Policymakers can prefer that outcome. They should say so.

The Bank’s own consultation launch note framed the project as supporting innovation while safeguarding financial stability. The rethink shows how hard it is to hold both goals at once when stablecoins start looking less like crypto instruments and more like payment rail competitors. Once a product is understood as monetary plumbing, reserve rules stop being housekeeping. They decide who can issue, who can earn, and which business models survive licensing.

Breeden’s comments do not signal that the Bank is about to abandon prudence, and the original caps may yet survive in some form. What shifted is the recognition that reserve design and user limits are not neutral guardrails. They allocate commercial advantage. If the UK wants a domestically supervised stablecoin sector with real scale, it will probably have to accept lower walls than it first proposed. Keep the walls high, and the market may still develop — just mostly somewhere else.