A non-domestic energy invoice contains up to a dozen separate charge types. Most businesses only check the total. Understanding each line identifies overcharges, incorrect VAT rates, and capacity charges that should not apply. The most common errors are estimated reads left uncorrected, Climate Change Levy applied at the wrong rate, and VAT charged at 20 per cent when 5 per cent applies.
Last reviewed: 12 May 2026
Why Most Business Energy Bills Are Harder to Read Than They Need to Be
Suppliers are not legally required to present non-domestic invoices in a standardised format. Unlike domestic bills, which Ofgem has pushed toward clarity through its billing licence conditions, commercial invoices vary significantly in layout and terminology between suppliers. The result is that the same charge can appear under different names on different bills, and charges that should be itemised are sometimes bundled into a single line.
Ofgem's Standard Licence Conditions for electricity and gas suppliers do require that invoices contain certain minimum information: the meter point reference, the period covered, the meter reads used, and the unit rate applied. Beyond that, the level of detail depends on your contract type and the supplier's billing system.
This guide walks through every component of a business energy invoice in the order they typically appear, explains what each one means, and identifies where errors are most commonly found.
Account Details and Supply Point Identifiers
The top section of any invoice should include your account number, the billing period, and the supply point reference. Two identifiers are critical:
MPAN (Meter Point Administration Number): The 21-digit reference for your electricity supply point, sometimes shown as the S-number or supply number. It is structured in two rows: the top row contains profile class, meter time switch code, and line loss factor; the bottom row is the core MPAN. Verify that the MPAN on your bill matches the number on your physical meter. A mismatch means you may be billed for a different property's supply.
MPRN (Meter Point Reference Number): The equivalent for gas, typically 10 digits. Used by Xoserve to identify your supply point in the national gas database.
Both identifiers stay with the property, not the occupant. If you recently moved into premises, check these match the address on the bill. Errors here are rare but when they occur they result in one business being billed for another's consumption.
Meter Reads: Actual vs Estimated
The meter reads section shows the opening and closing read for the billing period, the difference (the billed consumption), and whether each read is actual or estimated.
Estimated reads are generated by the supplier's system when no actual read has been submitted. They are based on your registered Annual Quantity (AQ) for gas or Estimated Annual Consumption (EAC) for electricity, spread across billing periods using a standard seasonal profile.
The problem with estimated reads is compounding error. If your actual consumption is lower than the AQ or EAC on file, you are overpaying and building up a credit. If it is higher, you are underpaying and will face a catch-up charge when an actual read is eventually obtained. Either way, estimated reads reduce billing accuracy.
Check each invoice for the letter or code indicating read type. Common codes include A (actual), E (estimated), C (customer read), and D (data logger for half-hourly sites). If more than two consecutive invoices show estimated reads, submit an actual read.
Unit Rate
The unit rate is the price per kWh of energy consumed. On a fixed-price contract, this is locked for the contract term. On a variable or flexible contract it may change monthly or quarterly.
The unit rate on your bill should match the rate in your contract documentation. Common discrepancies include:
- The bill using the rate from a previous contract that auto-renewed at a different rate
- Multiple rates being applied across a period where a contract change occurred mid-billing-cycle
- The wrong rate tier being applied on a two-tier tariff where a seasonal or volume discount should kick in above a threshold
Verify the unit rate against your contract schedule. On a pass-through or flexible contract the commodity rate will vary, but the method of calculation should be defined in the contract.
Standing Charge
The standing charge is a fixed daily cost covering the maintenance of your connection and the administration of your account. It applies regardless of consumption. Standing charges are expressed as pence per day and should be multiplied by the number of days in the billing period to arrive at the period charge.
Standing charges for business accounts range from around 25p per day for micro-sites to several pounds per day for medium and large sites. If your standing charge appears materially higher than at renewal, check whether the supplier has moved you onto a different rate following a contract change.
Capacity Charges: HH Sites Only
If your site has a half-hourly meter, the bill may include capacity-related charges that do not appear on non-half-hourly invoices:
Agreed Supply Capacity (ASC) or Available Supply Capacity charge: Levied by the Distribution Network Operator (DNO) and passed through by the supplier. Based on your Maximum Import Capacity (MIC) in kVA or kW, charged monthly regardless of whether that capacity is used.
Excess Capacity charge: If your measured demand in any half-hour period exceeds your agreed MIC, the excess is charged at a significantly higher rate, typically two to three times the standard capacity rate.
Reactive Power charge: Levied where the site's power factor falls below a threshold (usually 0.95 lagging). Poor power factor indicates inefficient use of the electrical supply and is penalised by the DNO.
For sites that were recently moved onto HH metering following the P272 mandate, capacity charges may appear on invoices for the first time. Check whether the ASC registered for your meter point reflects your actual operational requirements. Many businesses have ASC figures set at connection that are higher than current demand, resulting in ongoing capacity charge overpayment.
Climate Change Levy
The Climate Change Levy (CCL) is an environmental tax on energy supplied to non-domestic customers in the UK. It is levied per kWh of electricity and gas consumed and appears as a separate line on the invoice. The main rates from 1 April 2024 are set by HMRC and published annually.
CCL does not apply in the following circumstances:
- The supply is to a domestic property
- The energy is used for qualifying charitable non-business purposes
- The energy is supplied at the reduced rate for low-consumption customers
- The customer holds a Climate Change Agreement (CCA) with the Environment Agency, which entitles them to a reduced CCL rate
If CCL is charged on your bill and you believe an exemption or reduced rate applies, the mechanism for relief is a PP10 or PP11 levy relief certificate submitted to the supplier. Incorrectly charged CCL can be recovered by raising a formal billing dispute.
VAT on Business Energy
VAT on business energy is charged at 20 per cent as standard. However, a reduced rate of 5 per cent applies in specific circumstances. The qualifying conditions are covered in detail in the business energy VAT reduced rate guide. In summary:
- Electricity: if consumption is 1,000 kWh or less per month, the 5 per cent rate applies
- Gas: if consumption is 4,397 kWh or less per month (150 therms), the 5 per cent rate applies
- The supply is used for qualifying domestic or charitable non-business purposes
- The supply is part domestic and part business: the domestic portion qualifies for 5 per cent
The basis for this treatment is HMRC VAT Notice 701/19. VAT at 20 per cent applied to a bill that should be at 5 per cent is a material overcharge. For a business paying £3,000 per quarter on energy, the difference between 5 per cent and 20 per cent VAT is £450 per quarter.
Non-Commodity Costs on Pass-Through Contracts
If your contract is a pass-through or flexible contract, the invoice will itemise costs separately beyond the commodity (wholesale energy) element. Common non-commodity lines include:
Network costs: Transportation and distribution charges levied by the Transmission System Operator (National Grid) and DNO for electricity, or the Gas Transmission and Distribution networks for gas. These are set by Ofgem and adjusted periodically.
Balancing costs: Charges related to the cost of keeping the electricity system in balance. These include Balancing Services Use of System (BSUoS) charges, which were previously allocated to suppliers but were moved to generators from April 2023. On some pass-through contracts, residual balancing costs may still appear.
Renewables Obligation Certificates (ROCs): Suppliers are required to source a proportion of electricity from renewable generators holding ROCs. The cost of this obligation is passed through to business customers as a per-kWh charge.
Contracts for Difference (CfD) levy: The CfD scheme supports new renewable generation through a levy collected from suppliers and passed to generators when wholesale prices fall below the strike price. The per-kWh levy appears on pass-through invoices.
On a fixed-price contract, all of these costs are bundled into the unit rate and you do not see them itemised. On a pass-through contract, each line should correspond to a published industry cost. If a line appears that is not recognisable against published rates, query it with the supplier in writing.
How to Spot Common Billing Errors
The errors that appear most frequently on business energy bills are:
- Estimated reads not corrected after an actual read is submitted, resulting in a catch-up charge in a subsequent period without clear explanation
- CCL applied at the full rate when a CCA or exemption should reduce or remove it
- VAT at 20 per cent when the 5 per cent reduced rate applies
- Standing charge calculated for the wrong number of days when a billing period straddles a contract change
- Capacity charges based on an outdated MIC figure higher than current agreed capacity
- Incorrect unit rate following an auto-renewal where the new rate was not clearly communicated
If a billing error is identified, raise a formal written dispute with the supplier. Suppliers are required under Ofgem's Standard Licence Conditions to investigate billing complaints and respond within a defined period. The back-billing rules described in the business energy back-billing guide set limits on how far back a supplier can recover underpaid charges where the error was their fault.
Frequently asked questions
Editorial disclaimer: This information is provided for general guidance only. For specific billing disputes or tax advice on CCL and VAT, consult an energy adviser or tax professional.
What is the difference between an MPAN and an MPRN?
An MPAN is the 21-digit reference number for an electricity supply point. An MPRN is the equivalent reference for a gas supply point. Both stay with the property and are used by the energy industry to identify a specific meter location.
What does E mean on a meter read on my business energy bill?
E indicates an estimated read. The consumption for that period has been calculated by the supplier using a profile rather than an actual meter reading. Submit a meter read to correct it.
Is Climate Change Levy charged on gas as well as electricity?
Yes. CCL applies to both electricity and gas supplied to non-domestic customers. The per-kWh rates differ for electricity and gas and are updated by HMRC annually.
Can I reclaim VAT if my supplier charged 20 per cent instead of 5 per cent?
If your consumption qualifies for the 5 per cent reduced rate and your supplier charged 20 per cent, you can raise a billing dispute and request a VAT correction. The supplier should issue a credit note for the difference. You may also need to adjust your VAT returns.
What is a pass-through electricity contract?
A pass-through contract separates the wholesale commodity cost from the non-commodity costs (network, balancing, levies). You pay the actual non-commodity costs as they are published each period rather than a bundled unit rate that includes the supplier's estimate of those costs. Pass-through contracts suit businesses that want transparency and are willing to accept cost variability.
How we verified this
This article draws on published guidance from Ofgem, the Department for Energy Security and Net Zero, and the primary legislation and regulatory sources listed in the Sources section. No aggregator or supplier-produced content was used as a primary source.
