Migration Impact
See exactly how DUoS charges change when a site moves from aggregated to site-specific settlement under MHHS.
For energy consultants, portfolio managers and suppliers preparing clients for the MHHS transition.
Try Migration ImpactCharges increase under MHHS
Q1 2025-26 · East Midlands · 200 kVA
net increase, 21.9% higher
| Charge | Current | After MHHS | Change |
|---|---|---|---|
| Unit charges | £2,400 | £2,150 | -£250 |
| Fixed charge | £200 | £180 | -£20 |
| Capacity charge | £0 | £840 | +£840 |
| Total DUoS | £2,600 | £3,170 | +£570 |
The journey
Four steps, one clear picture
From an MPAN to a charge-by-charge before/after comparison in under a minute.
Enter
Enter MPAN and consumption
Provide the supply point MPAN, billing period and annual Elec consumption. Enter the agreed kVA from the connection agreement or let the tool estimate from usage data.
Identify
Identify the current tariff
We decode the MPAN to confirm the supply point is on an aggregated tariff, read the DNO region and profile class, and verify the site is eligible for an MHHS comparison.
Map
Map to the post-MHHS equivalent
We pair the current aggregated tariff code with the correct site-specific equivalent so the comparison uses the real tariff the site will move to, not a generic estimate.
Tariff transition
Current charge composition
Compare
See the impact side by side
Unit, fixed and capacity charges shown before and after MHHS with the per-component delta. A capacity charge is introduced under site-specific settlement: the net effect is up or down depending on the load profile.
Charges increase under MHHS
Q1 2025-26 · East Midlands · 200 kVA
net increase, 21.9% higher
| Charge | Current | After MHHS | Change |
|---|---|---|---|
| Unit charges | £2,400 | £2,150 | -£250 |
| Fixed charge | £200 | £180 | -£20 |
| Capacity charge | £0 | £840 | +£840 |
| Total DUoS | £2,600 | £3,170 | +£570 |
The problem
MHHS will change charges - but by how much?
Market-wide Half-Hourly Settlement means charges will be based on actual half-hourly consumption, not estimated profiles. For some sites this is good news; for others, it means higher costs. The challenge is helping clients understand which camp they're in.
Without understanding MHHS impact, you can't advise clients on the transition, help them prepare, or make the case for load management investments.
Why it matters
What you walk away with
Side-by-Side Tariff Comparison
See current aggregated tariff rates alongside the site-specific rates the site will move to.
Charge Impact Analysis
Understand how unit, fixed, and capacity charges will change under MHHS.
Percentage Change Indicators
See clear percentage increases or decreases for each charge component.
Built on official published rates
FAQ
Answers, before you ask
Market-wide Half-Hourly Settlement is a major industry change requiring all meters to settle on actual half-hourly consumption rather than profiled estimates. Full rollout is expected by 2027.
Still curious? Email [email protected]
Know the MHHS impact before it arrives.
Unit, fixed and capacity charges compared side by side for any aggregated supply point.