The Nuclear RAB Levy is a new non-commodity cost applied to electricity bills to help finance the UK’s next generation of nuclear power stations (starting with Sizewell C).
Suppliers are legally required to collect it and pass it on.
You will see this appearing in quotes from 2025 onwards. Some suppliers build it into the unit rate; others show it as a separate line item. This means comparisons will get messier unless you know what you are looking for.
The government is switching to a Regulated Asset Base (RAB) model for nuclear projects:
Nuclear stations cost billions and take a decade to build.
Instead of waiting for the plant to be finished, the RAB model spreads costs across consumers and investors from day one.
This reduces financing risk and accelerates construction.
In simple terms:
You are pre-paying for the privilege of having stable nuclear in the future.
The levy is expected to start being charged by suppliers around November 2025 onwards, though some may incorporate it earlier depending on forecasts and contract structures.
The scheme runs through the construction phase of Sizewell C, and potentially additional nuclear plants.
Current indicative rates (subject to government updates):
Interim Levy Rate: approx £3.455 per MWh
(≈ 0.3455p/kWh)
Operational Cost Levy: negligible (≈0.0028p/kWh)
Rates may be revised annually as project costs change.
For a 100,000 kWh business, this adds roughly:
~£345 per year just in the levy.
Multiply that for large users.
This part is crucial for brokers.
Different suppliers are implementing it differently:
The customer never sees a separate line.
But their price per kWh is higher.
Shows as a line item on the contract or bill.
Unit rate looks lower, but total cost is the same once levy is applied.
Some suppliers are quietly adding a buffer into fixed prices to protect themselves from future rate changes.
Mostly for flexible or non-fixed products.
This levy makes “simple price comparison” even more dangerous.
Two suppliers could show you:
a 28p rate (with levy embedded), versus
a 27.6p rate (levy separate at 0.3455p)
The second one looks cheaper but isn’t.
Brokers must ensure they are comparing like with like.
For fixed contracts:
Check if the levy is included or itemised.
For pass-through contracts:
Assume levy is added separately unless stated otherwise.
Ask suppliers:
“Is the RAB levy included in your unit rate?”
“If not, how is it itemised?”
Do not compare a rate with the levy included against one without.
Script for you:
“The government has added a new nuclear levy which suppliers must pass through. Some include it in the unit rate, others show it separately — so rates need to be compared on a like-for-like basis.”
Suppliers may adjust renewal pricing earlier to account for expected levy changes.
This levy compounds; 500,000 kWh = £1,700+ a year before VAT.
Some exemptions or reductions may apply.
Supplier will confirm — do not guess.
No. It is a regulatory obligation.
No. This is why brokers must read supplier notes carefully.
Yes, likely — nuclear project costs are reviewed periodically.
No. Electricity only.
Of course. Blame the government, not the supplier.
This charge is not negotiable, not avoidable, and not a supplier “taking the mick”.
It is a government-backed nuclear financing scheme that every supplier must follow.
As a broker, your job is simple:
Know which suppliers include it
Know which suppliers don’t
Compare like with like
Explain it calmly to customers
Everything else is noise.