The UK's PQC Guidance Just Got More Specific. It's Still Not a Rule.

NCSC published something new about UK post-quantum cryptography on 15 October 2026. It isn't a new deadline, and it isn't a new rule -- it's a more specific answer to a question most organisations haven't gotten to yet: once you decide to migrate, which exact cipher suites do you actually configure.

What changed, specifically

NCSC's TLS guidance update, published 15 October 2026, followed the IETF's publication of RFC 10024 (Post-quantum traditional hybrid key agreement mechanisms for TLS 1.3). The update is concrete in a way most national PQC guidance isn't: it recommends specific cipher choices, both hybrid post-quantum/traditional and pure-PQC, notes that hybrid configurations are currently the most widely deployed in commonly-used libraries, and states plainly that "TLS 1.3 is the only version that supports PQC."

Crucially, the update doesn't move the UK's existing deadlines -- it reaffirms them. NCSC states directly: "we recommend that high priority migration activities should be carried out by 2031," and that organisations "should be aiming to make this move now." This is implementation detail layered onto an existing timeline, not a new commitment.

The timeline underneath it, unchanged

NCSC's "Timelines for migration to post-quantum cryptography" sets three milestones, in force since March 2025 and unrevised since: by 2028, a full discovery exercise, defined migration goals, and an initial migration plan; by 2031, early and highest-priority PQC migration activity, with the plan refined into a thorough roadmap; by 2035, complete migration across all systems, services, and products. NCSC frames the ten-year window (2025-2035) as "a sufficient period for a rich set of PQC standards to appear, for an ecosystem of products that uses them to be developed, and for uptake to become widespread."

That 2028 discovery-exercise milestone is where a cryptographic inventory lives in practice, even though NCSC's guidance never uses the term. You can't complete "a full discovery exercise" without first finding out what cryptography your organisation actually runs -- the substance of a CBOM, delivered under different language.

None of it is binding. NCSC's own framing is guidance for organisations to self-assess against, with no fines, audits, or certification mechanism attached to any of the three dates.

The Bank of England is further along than it gets credit for

Most coverage of UK PQC policy treats NCSC's guidance as the whole story and leaves financial regulation as a footnote. That undersells what the Bank of England has actually published. An October 2025 Bank of England document on innovation in AI, distributed ledger technology, and quantum computing devotes a real section to post-quantum cryptography -- naming "harvest now, decrypt later" as a defined risk, disclosing that the Bank has developed risk scenarios for post-quantum threats, and stating it's piloting a PRA supervisory briefing on quantum risks specifically. The Bank also co-chairs the G7 Cyber Expert Group alongside the US Treasury, giving it direct visibility into the multilateral PQC coordination effort most other jurisdictions reference secondhand.

That's genuine, independent regulatory engagement -- not NCSC's timeline restated by a different body, but the Bank doing its own risk-scenario work and piloting its own supervisory tool. It still isn't a rule. No PRA supervisory statement or binding requirement has resulted from it as of this writing.

The FCA, by contrast, has published less than its name recognition might suggest. Its one relevant document -- an October 2025 research note on quantum computing applications in financial services -- explicitly disclaims representing the FCA's official position, and covers quantum computing use cases like portfolio optimisation and fraud detection rather than post-quantum cryptography specifically. The FCA's more substantive contribution is founding membership of the UK Quantum Regulators Forum, a real coordination body launched with official government terms of reference in April 2025 -- useful institutional infrastructure, but not itself a PQC or cryptographic-inventory requirement.

What's still just a bill

The Cyber Security and Resilience Bill, working through Parliament as of this writing, amends the NIS Regulations 2018 to expand scope -- data centres, large load controllers, managed service providers, critical suppliers -- and strengthens incident-reporting and enforcement powers. Based on available descriptions of the bill, it contains no cryptographic-inventory, CBOM, or PQC-specific provision. If you're tracking it as a potential vehicle for a future binding UK PQC requirement, it isn't one yet, and nothing in its current content suggests it will become one directly.

What to do with this

If you're a UK organisation of any kind, NCSC's 2028 discovery-exercise milestone is closer than the 2035 headline date makes it feel, and the October TLS update gives you the first genuinely actionable technical detail -- specific cipher suites -- to act on rather than a general direction to plan toward. If you're in UK financial services, the Bank of England's own risk-scenario work is a stronger signal about where PRA supervisory expectations are heading than NCSC's guidance alone suggests, even without a binding instrument yet.

Either way, the discovery exercise NCSC's 2028 milestone requires is the same underlying work every PQC regime on this tracker eventually asks for: an honest, current account of where cryptography actually runs across your systems.

The United Kingdom country page tracks both tracks with their primary sources.