Updates to Schedule 14 Measurement Transformers Commissioning Timescales

Why the change is required

The current REC‑mandated commissioning process takes up to 85 working days (WDs) end‑to‑end. Under MHHS, RF will occur just ~88 WDs after consumption, meaning:

• Defects may be discovered at or after RF.
• Settlement errors could become irreversible.
• Parties (DNOs, MOAs, Suppliers) could be held liable for issues they cannot correct.
• Calendar effects (e.g., Easter + early May bank holidays) can push commissioning beyond RF.

This creates an industry‑wide settlement and compliance risk.

What the Change Proposal aims to achieve

The proposal does not change technical commissioning requirements (BSC CoP4), only the REC timescales.

It aims to:

• Ensure commissioning is always completed before RF.
• Reduce the likelihood of defects “crystallising” into Settlement.
• Improve end‑to‑end coordination between DNOs, MOAs and Suppliers.
• Establish a realistic and enforceable SLA framework under MHHS.

Two initial options are in development:

• Option A: Reduce the overall chain from 80 → 70 WDs
• Option B: Reduce from 80 → 60 WDs

(Subject to Impact Assessment and CHIG data.)

Key operational challenges

Panel discussions highlighted several constraints:

• Third‑party operatives (customer‑appointed installers) remain outside licensed control.
• DNO and MOA workforce capacity already stretched in some regions.
• Appointment lead‑time variability affects commissioning speed.
• BSC auditors monitor processes, not REC timescales—so REC must set realistic, evidence‑based SLAs.

These factors will strongly influence final timescale decisions.

Impacts

Consumers

• Fewer long‑term billing inaccuracies and Settlement errors.
• Reductions in unnecessary site revisits.

REC Parties

• Suppliers: Faster resolution of commissioning blockers.
• MOAs: Accelerated on‑site commissioning expectations.
• DNOs: Potential tightening of CT/VT commissioning from 16–21 WDs.
• No cross‑code impacts expected, but tracked via CCSG for BSC/DCUSA interactions.

Risks Identified

• Operational capacity constraints (MOA/DNO resource).
• Non‑licensed installer delays outside party control.
• Settlement crystallisation risk if commissioning remains too long.
• Compliance burden if deadlines are shortened too aggressively.
• Industry readiness to update systems and processes.

Timeline (from Proposal Plan)

• Dec 2025 – Apr 2026: Initial Assessment & Solution Development
• Feb – Apr 2026: Impact Assessment & Business Case
• May – Jun 2026: Consultation
• Jul – Aug 2026: Final Determination & Panel Vote (12 Aug)
• 13–27 Aug 2026: Appeal Window

This ensures implementation well ahead of MHHS M16 (Jul 2027).

Current status and next steps

• REC Code Manager issuing the Impact Assessment.
• CHIG will gather real‑world data (current SLA performance distribution).
• Industry responses will shape whether 60WD, 70WD or an alternative is viable.
• Evidence‑based refinement will follow before consultation.

Executive‑Level Takeaway

I0284 is a preventative, MHHS‑critical change ensuring commissioning completes within the compressed 4‑month Settlement timetable.
It reduces the ~85WD chain to a shorter, deliverable timeframe, balancing MHHS compliance with operational reality.

The REC Change Panel supports the current plan, and emphasises:

• Timescales must be achievable, not aspirational.
• Installer and DNO/MOA operational constraints must be reflected.
• Evidence from IA and real site data is essential to setting the new SLAs.

The change is strategically important, risk‑reducing, and time‑sensitive—requiring progression during 2026 to avoid compressing the industry ahead of MHHS go‑live.#

The REC Code Manager is planning to attend the AMO’s HHEMF 26-01, 19 February 2026, to discuss the issue.