United Kingdom
ExecutingNCSC's 'Timelines for migration to post-quantum cryptography' guidance sets three dated phases: by 2028 complete discovery and assessment and build an initial migration plan; by 2031 complete migration of the highest-priority systems and refine the plan; by 2035 complete migration across all systems and services.
Guidance, not statute — but it is the reference schedule UK regulators and CNI operators are being measured against, and NCSC's 2025 Annual Review tracks it as a live national programme.
UK organisations generally, with government, critical national infrastructure, telecoms and finance treated as priority sectors
Band rationaleFinal published guidance with the clearest whole-economy phasing, but no statutory instrument behind it.
- 2028
Discovery and initial plan
Cryptographic discovery and assessment complete; migration objectives and a costed initial plan in place.
Bindingness · guidance - 2031
Highest-priority migration complete
Highest-priority, highest-risk systems migrated; plan refined for the remainder.
Bindingness · guidance - 2035
Migration complete
Migration completed across all systems, services and products.
Bindingness · guidance
The UK model makes discovery a dated deliverable in its own right, which is the step most organisations actually fail first.
- ·Build the cryptographic inventory before choosing algorithms — 2028 is a discovery deadline, not a deployment one
- ·Tie priority tiers to data lifetime, not system age
- ·Bespoke and legacy estates need their own programme and budget line
- A2guidanceTimelines for migration to post-quantum cryptographyNCSCPublished 2025-03-20Reviewed 2026-09-06
- A2guidancePQC migration timeline chartNCSCReviewed 2026-09-06
- A2guidanceCyber chiefs unveil new roadmap for post-quantum cryptography migrationNCSCReviewed 2026-09-06
- A3finalAnnual Review 2025 — migrating to post-quantum cryptographyNCSCPublished 2025Reviewed 2026-09-06