Reading Between the Unit Rate: A Line-by-Line Audit of a Winter Energy Offer
Business energy procurement rarely fails because the unit rate is a fraction too high. It fails because the buyer cannot see what the rate is meant to cover. As the 2026/27 renewal season approaches, many UK organisations will still receive a quote dominated by one pence-per-kWh number and a standing charge. That single figure may be competitive, but it is not self-explanatory.
A fixed-price offer is a bundle. It contains a wholesale energy curve, a shape adjustment for your consumption profile, winter risk, network and capacity charges, policy and levy costs, credit cover, supplier margin and, often, broker remuneration. The supplier does not have to disclose every line in full. The buyer can, however, insist on a component schedule that makes the offer testable.
Start With Your Load Shape, Not the Headline
Before comparing suppliers, establish the basis of the quote. Is it for a half-hourly supply with a profiled shape, or a non-half-hourly supply using a deemed profile? Does the supplier price your actual seasonal consumption, or apply a generic winter uplift? For a business with strong winter peaks, the shape assumption can matter more than a small difference in the headline rate.
Ask each supplier to confirm the delivery period, the volume assumption and the profile used. A quote that cannot state its start and end dates, or the consumption profile behind it, is difficult to benchmark and harder to challenge later.
The Components Behind the Pence
Wholesale curve
This is the traded baseload cost for the delivery period. It is not a forecast of your bill; it is one input. Benchmark it against a public wholesale curve for the same delivery window, adjusted for the timing of the quote. A red flag is a supplier or broker who cannot state the delivery period or explain why the wholesale element has moved.
Shape and winter risk
Your consumption is not flat. Winter working hours, early darkness and heating loads can push consumption into periods when wholesale prices are higher. The supplier prices that mismatch through a shape premium or an uplift. Ask for the shape cost in pence per kWh, or at least the assumed peak percentage. Compare two offers using the same load profile. A single unexplained uplift is not a benchmark; it is a guess.
Network and capacity charges
Transmission and distribution charges, capacity market costs and metering charges may be fixed or passed through. If they are pass-through, ask for the published tariff basis and confirm that reconciliation will appear on the invoice. If they are fixed, ask what assumption sits behind them. Bundling network costs into a unit rate without a reconciliation mechanism makes it difficult to see whether you are paying for your own capacity or someone else's.
Policy and levy costs
Renewables Obligation, Contracts for Difference, Climate Change Levy and supplier obligations are largely pass-through costs. They should be identifiable. A line labelled 'environmental' with no rate, source or consumption basis is not a disclosure. Ask for the levy rates used and confirm whether they will be reconciled if the published rates change before delivery.
Credit cover
Suppliers price credit risk. A business with a modest credit rating may be asked for a security deposit, a letter of credit or extended payment terms. Ask how the collateral is calculated and whether the cost appears as a separate charge or is buried in margin. A credit charge is not automatically unfair, but it should be visible enough to compare with another supplier's terms.
Supplier margin and broker fee
Supplier margin is legitimate. Broker remuneration is also legitimate, provided it is disclosed. Ask for total remuneration in writing, including any commission embedded in the unit rate. Compare offers on a net basis where possible. If a broker refuses to disclose commission, treat the offer as incomplete rather than competitive.
Standing charge, metering and VAT
The standing charge covers fixed costs such as metering and administration. Confirm what is included and whether meter operator charges are separate. VAT should be shown clearly, with any reduced-rate eligibility confirmed in writing.
A Practical Benchmarking Table
| Component | What to ask for | Benchmark test | Red flag |
|---|---|---|---|
| Wholesale energy | Delivery period, volume, curve reference | Compare implicit wholesale cost with a public curve for the same period | No delivery dates or vague 'market price' wording |
| Shape and winter risk | Load profile, peak percentage, shape uplift in p/kWh | Compare suppliers using the same consumption profile | Unexplained winter premium that cannot be tested |
| Network and capacity | TNUoS, DUoS, capacity market, fixed or pass-through | Match pass-through charges to published tariffs and your capacity | 'Network' bundled into unit rate with no reconciliation |
| Policy and levies | RO, CfD, CCL, supplier obligation rates | Compare rates with published sources and your consumption | 'Environmental' line without rate or source |
| Credit cover | Credit assessment, collateral calculation, payment terms | Ask for cost in pounds or p/kWh and compare terms | Credit charge hidden inside margin |
| Margin and broker fee | Fixed margin, total remuneration disclosure | Compare net offers and request commission in writing | Broker refuses to disclose commission |
| Standing charge and VAT | Included services, meter operator charges, VAT rate | Check fixed costs against another offer and confirm VAT treatment | VAT assumptions not shown |
Questions to Put in Writing Before You Sign
First, which wholesale curve and delivery period underpin the offer? Second, what shape premium is included, and how would it change if we shifted load away from winter peaks? Third, which charges are fixed and which are pass-through? Fourth, what credit cover is required and how is it calculated? Fifth, what is the total broker remuneration, including any commission? Sixth, what happens if our consumption differs from the quoted volume by 10% or 20%?
These questions do not require the supplier to reveal its entire cost stack. They require enough evidence to compare offers on a like-for-like basis and to understand what happens after signature.
Negotiation Levers That Actually Move
Volume tolerance, payment terms, credit cover and contract length often move the price more than a hard stance on the headline unit rate. A business that can offer a clearer consumption forecast, a stronger credit profile or a willingness to shift some load may negotiate a better shape assumption. A buyer who focuses only on the pence-per-kWh figure may win the headline and lose on pass-through charges, capacity reconciliation or credit costs.
Keep the Audit Trail
Store the quote assumptions, component schedule, correspondence and final contract in one place. When the first invoice arrives, compare the unit rate, standing charge, capacity charge and pass-through lines with the agreed schedule. Set a review date before the next renewal. The aim is not to reconstruct the supplier's book; it is to make sure that the next renewal conversation starts from evidence rather than a single number.
For ExEnergy readers, the discipline is straightforward: treat a winter energy offer as a set of priced assumptions. Test each assumption. Where it cannot be tested, ask why. That is how a procurement strategy becomes cost control rather than a leap of faith.
