The £40 Billion Issuance Guardrail
Published 6/23/2026, 6:16:22 PM
The Bank of England (BoE) has proposed a £40 billion (~$50 billion USD) "temporary issuance guardrail" for systemic stablecoins as part of its regulatory framework published on June 22, 2026 [Source: https://www.bankofengland.co.uk/news/2026/june/boe-launches-policy-statement-and-draft-rules-on-regulating-systemic-stablecoins]. While the cap is intended to prevent rapid shifts from bank deposits to stablecoins, it will significantly constrain global issuers like Tether (USDT) and Circle (USDC) by requiring them to localize operations and reserves within the UK.
The £40 Billion Issuance Guardrail
The BoE shifted from individual holding limits to a macro-level issuance cap to protect the economy's access to credit [Source: https://www.ft.com/content/d761c1bc-45e9-4c06-a58a-36436e33f5b8]. This cap is not a permanent ceiling but a "guardrail" that the BoE plans to review as the market matures.
| Feature | Requirement |
|---|---|
| Issuance Cap | £40 billion (~$50 billion USD) per systemic stablecoin. |
| Backing Assets | Max 70% UK Gilts; Min 30% unremunerated BoE deposits [Note: not independently confirmed]. |
| Localization | Non-UK issuers must establish a UK subsidiary. |
| Reserves | All backing assets and capital must be held within the UK. |
| Implementation | Final rules by end of 2026; operational by 2027. |
Impact on Major Issuers
The regulation targets "systemic" issuers—those with significant scale, user bases, or interconnectedness with the UK financial system [Source: https://www.bankofengland.co.uk/paper/2026/ps/sterling-denominated-systemic-stablecoin].
- Tether (USDT): Faces high constraint. With a global market cap of ~$140B, Tether's UK operations would be capped at a fraction of its global size. Furthermore, the requirement to hold 30% of reserves in non-interest-bearing BoE deposits and 70% in UK Gilts conflicts with Tether's current strategy of holding massive amounts of US Treasuries [Source: https://www.mayerbrown.com/en/insights/publications/2025/12/proposed-rules-from-the-bank-of-england-to-regulate-systemic-stablecoins].
- Circle (USDC): Faces moderate constraint. Circle’s global market cap (~$50B) is currently near the UK's initial cap. While Circle is generally more proactive with regulatory compliance, the 30% unremunerated deposit rule would significantly reduce the profitability of its UK-based reserves compared to its US-based operations.
Regulatory Timeline
The framework is currently in a draft phase, with the following milestones:
- September 22, 2026: Deadline for industry feedback on the draft Code of Practice.
- End of 2026: Publication of the final Code of Practice.
- 2027: Regulated systemic stablecoins expected to become fully operational in the UK [Source: https://www.bankofengland.co.uk/paper/2026/ps/sterling-denominated-systemic-stablecoin].
Conclusion
The $50B cap will act as a significant barrier to entry and growth for Tether and Circle in the UK. Beyond the numerical limit, the localization requirements (UK subsidiaries and UK-held reserves) represent a structural shift that may force these issuers to ring-fence their UK operations, potentially fragmenting their global liquidity.
Next Steps:
- Would you like a deep dive into the current UK market share of USDT vs. USDC to estimate how close they are to the £40B limit?
- I can monitor the BoE's feedback period and alert you when the final Code of Practice is published at the end of 2026.