The capital floor drops to 1%: the FCA finishes the light half of Britain's two-speed stablecoin regime.

The capital number moved. The two-regulator split is the structure it now sits inside, and that structure was fixed eight days earlier.

The FCA closed five separate consultation tracks into fixed text on 30 June. Rate each by what moved since the last draft, not by what the press release calls it.

The capital coefficient is the only figure that moved between draft and final. Everything else is the same architecture the FCA has consulted on since 2023, now fixed in text.

The FCA's 30 June rules and the Bank of England's 22 June rules are not two regimes. They are two tiers of one regime, and the boundary between them is a judgment call, not a formula.

• The FCA's track is lighter by design. Lower capital, a broader reserve mix, slower redemption. That is the price of not yet mattering to financial stability.
• The gate has no formula. HM Treasury's holistic assessment is the same undefined threshold the Bank of England's own 22 June rules left open. Finishing the FCA's half did not close it.

The cut is a competitiveness bet, not a risk reassessment. The GENIUS Act applies one reserve rule (100% cash and T-bills) to every licensed US issuer regardless of size, with no separate capital coefficient. MiCA applies a flat 30% central-bank-deposit floor to every e-money token issuer in the EU. The FCA is the first of the three to grade the reserve and capital rule by systemic status rather than apply one number to everyone from day one, and it moved that number down before a single firm has been authorized under it.

The custody bright line closes a three-year ambiguity. Since the 2023 Financial Services and Markets Act extended the FCA's cryptoasset perimeter, whether a firm counted as a custodian turned on judgment calls about control and intent. The 24-hour holding test and the override-authority test replace that with a fact any firm can check against a clock, not a case-by-case argument with a supervisor.

The split creates an incentive to stay just under the line. An issuer growing toward systemic scale faces a discontinuous jump, not a gradual one: 1% capital and a 10% core-asset floor becomes 70% gilts, 30% unremunerated deposits, and a £40 billion issuance cap the moment HM Treasury designates it systemic. Because that designation is qualitative, an issuer cannot underwrite the crossover. It can only guess at what usage pattern trips it, which is a different commercial problem than any single-tier reserve rule creates.

• No quantitative systemic threshold exists. HM Treasury's Banking Act 2009 "holistic assessment" is the same undefined test the Bank of England's 22 June rules left open. The FCA's 30 June rules do not resolve it either.
• Nothing is enforceable for sixteen months. The authorization window does not open until 30 September 2026, and the regime does not bind until 25 October 2027. Every number in this rulebook is draft-in-practice until firms apply and are approved.
• A lower capital coefficient is not a lower reserve requirement. The 1% figure is a solvency buffer on top of full backing, not a substitute for it. The FCA has not specified what sits inside the "wider permitted set" for the roughly 90% of reserves outside the core-asset floor, a gap the Bank of England closed for systemic issuers with an explicit 70/30 split.
• The FCA's own stablecoin sandbox participants are not sorted yet. Revolut, Monee Financial Technologies, ReStabilise, and VVTX have been rehearsing under the FCA's sandbox since before this rulebook existed. Neither regulator has said which of the four will apply under the qualifying track and which has the consumer scale to draw an early systemic look.
• The market-abuse and gatekeeping obligations are untested law. A statutory crypto market-abuse regime and a platform-disclosure repository are both new to the UK. Enforcement capacity and case law do not yet exist to show how hard either one bites.

This briefing completes what the 22 June Bank of England briefing opened. The Bank and the FCA describe the sequencing themselves: an "end-to-end regime" with a "managed transition" as issuers grow from non-systemic to systemic. Eight days separate the two halves; neither publication makes sense read alone.

Set against the other two live stablecoin architectures, the UK's design is the outlier. The GENIUS Act applies a single 100% cash-and-T-bill reserve rule to every licensed US issuer, with OCC final rules due 18 July 2026 to fix the remaining detail. MiCA applies a flat 30% central-bank-deposit floor to every EU e-money token issuer, large or small, a threshold already locked in by the deadline covered in the 1 July MiCA briefing. Both are single-tier rules that do not change with scale. The UK is the only one of the three that scales the requirement to realized systemic significance rather than applying one number from day one.

That bet inherits the gap the 23 June BIS Annual Economic Report briefing flagged in general terms: stablecoin oversight architectures worldwide lack a clean definitional line for when a private instrument becomes systemically relevant. The UK's two-tier design is the most concrete attempt yet to operationalize a graduated answer. It is still not a numeric one.

The FCA completed the non-systemic tier of the UK's stablecoin regime eight days after the Bank of England completed the systemic tier, and the one number that moved between draft and final, the capital coefficient falling from 2% to 1%, signals that the FCA is optimizing for hub competitiveness at the light end while trusting the Bank of England's heavier rules to catch what becomes systemically relevant. That trust depends entirely on HM Treasury's holistic assessment working in practice, and no version of this rulebook, on either side of the split, has published what that assessment looks like in numbers.

Watch three things:

• The first cohort of applications, 30 September 2026 to 28 February 2027. Whether the FCA's existing sandbox names, Revolut, Monee Financial Technologies, ReStabilise, and VVTX, apply under the qualifying track or signal systemic scale from day one is the first real read on how the two tiers sort in practice.
• The first HM Treasury systemic designation under the Banking Act 2009 holistic-assessment test. This is the event that turns the boundary between the FCA's 1%/10% track and the Bank of England's 70/30 track from a description into a precedent.
• OCC's GENIUS Act final rules, due 18 July 2026. The direct transatlantic comparison: a flat, non-graduated US reserve rule against the UK's two-tier design, decided just eighteen days after this rulebook closed.