Energy Suppliers Overcharged 34,000 Customers: Refunds Guide

If you’ve ever opened an energy bill and felt your stomach drop, you’re not alone. A recent Ofgem review found 34,000 UK customers had been overcharged — some for years — due to multiple standing charges stacking up on properties with more than one electricity meter. The good news is that regulators are now forcing suppliers to clean up their billing acts, with new rules coming into force in 2026. This guide walks you through the real cases, what the numbers mean, and exactly what steps you can take if you suspect you’ve been charged too much.

Overcharged customers: 34,000 · Total redress ordered: £7,029,648.63 · Suppliers involved: 10

The table below summarises the key figures from the overcharge scandal across UK and Irish energy suppliers.

Can you be overcharged with a smart meter?

Smart meters promised accurate, real-time billing — yet they have become a source of billing disputes. When these devices malfunction or fail to communicate properly with the supplier’s systems, customers can end up paying based on estimated readings rather than actual consumption.

Smart meter billing errors

The core problem stems from meters with restricted infrastructure — specifically properties with multiple electricity meters that ended up receiving duplicate standing charges. According to MoneyWeek’s analysis of Ofgem data, this affected customers from January 2019 through September 2024. The overcharges occurred when multiple standing charges were applied in ways that exceeded the price cap meant to protect consumers.

ESB Networks glitch case

Across the Irish Sea, ESB Networks reportedly overcharged customers for over a decade due to a smart meter communication glitch. Each affected customer received €50 in compensation. Unlike the UK system, Ireland lacks a published dataset of overcharge cases, making it harder to gauge the full scale of billing errors in the Republic.

Why Did Your Electric Bill Go Up After Installing a Smart Meter?

There are several common reasons why customers see bill increases after smart meter installation, ranging from correcting previous underestimates to genuine technical faults.

Common reasons for bill increases

• Estimated readings corrected: If your previous bills were based on estimates (common with older meter reads), switching to a smart meter’s automatic readings can reveal actual usage that was previously underbilled.
• Multiple meter infrastructure: Properties with restricted meters — those with limited capacity handling multiple electricity supplies — can trigger duplicate standing charges.
• TARIFF changes: Some suppliers use smart meter installation as a trigger to move customers onto different tariff structures.

Technical glitches reported

Beyond corrections, actual technical faults have been documented. In some cases, smart meters failed to transmit readings correctly, leading to either overestimation or underestimation of consumption. Ofgem’s new Guaranteed Standards, effective 23 February 2026, now mandate automatic £40 compensation when smart meter installation issues are not resolved within prescribed timeframes.

Which Energy Company Has the Least Complaints?

Customer satisfaction and complaint rates vary significantly across UK energy suppliers, with some providers handling billing errors far better than others.

Complaints rankings 2026

Based on available data, Octopus Energy and Utility Warehouse topped the list of suppliers implicated in the overcharge scandal — but this reflects their market share size rather than necessarily higher complaint rates. Companies with fewer customers may simply have had fewer affected accounts.

Best and worst suppliers

The overcharge review identified 10 suppliers total, with Octopus Energy accounting for 20,862 affected customers (£2,636,884 owed) and Utility Warehouse covering 8,272 customers (£2,043,098.84 in refunds). Smaller suppliers also appear in the data, though the full list remains unpublished. Customers switching between suppliers should verify their new provider’s complaint handling track record through Citizens Advice or the Energy Ombudsman.

How Do You Complain About Your Electricity Supplier?

When you spot an overcharge on your energy bill, the path to resolution follows a clear escalation ladder — starting with your supplier directly and moving to independent regulators if needed.

Contact supplier first

Your first step should always be contacting your energy supplier directly. Under Ofgem’s rules, suppliers must refund credit balances on closed accounts within 10 working days. They must also send final bills within six weeks of you switching suppliers — breach of this triggers £40 compensation. When raising a complaint, cite specific meter readings, bill periods, and amounts to help their investigations.

Escalate to ombudsman

If your supplier fails to resolve the overcharge within eight weeks, or if you remain unsatisfied with their response, you can escalate to the Energy Ombudsman. This independent body handles billing disputes and can award compensation. For Ireland, the Commission for Regulation of Utilities (CRU) provides guidance on complaint procedures, though no equivalent ombudsman scheme operates at the scale of the UK’s Energy Ombudsman.

What Refunds Are Energy Companies Paying Customers?

The scale of energy company refunds in 2024-2026 represents one of the largest consumer redress exercises in the UK’s recent regulatory history.

Ofgem secured payouts

Ofgem’s review resulted in total redress of £7,029,648.63, comprising £5,645,963.37 in direct refunds and £1,383,685.26 in goodwill payments. The ten suppliers involved must refund affected customers, with most multi-meter customers receiving automatic refunds if they stayed with the same supplier throughout the overcharging period (January 2019 to September 2024).

UK and Ireland cases

In the UK, the compensation process is largely automated. Customers who changed suppliers during the overcharging period may need to lodge claims directly with their former provider. In Ireland, the ESB Networks case saw each affected customer receive €50 — a smaller individual payout, but the problem reportedly spanned over a decade of incorrect billing. Ireland-specific regulatory data on overcharge cases remains limited compared to the detailed Ofgem disclosures.

The regional claim limitation periods affect how long customers have to pursue overcharge disputes.

How to Check If You’re Owed a Refund

Identifying whether you’re owed money from an energy overcharge requires checking your billing history and understanding how multiple meters might have affected your charges.

• Review past bills: Check whether you were charged multiple standing charges for properties with multiple electricity meters. Your MPAN (Meter Point Administration Number) can reveal if you have multiple supplies registered.
• Contact your supplier: Ask specifically whether your account was reviewed as part of the multi-meter overcharge remediation. Suppliers conducting annual reviews should identify eligible accounts automatically.
• Check refund timelines: If you’ve switched suppliers, your new supplier may not have your historical data. Contact your previous supplier to confirm whether a refund is owed.
• Document everything: Keep copies of old bills, correspondence, and meter readings as evidence if you need to escalate a complaint.

New Smart Meter Rules: What Changes in 2026

The UK government and Ofgem have introduced tougher standards for smart meter functionality, with new rules taking effect in 2026 that significantly strengthen consumer protections.

• 90-day fix rule: From early May 2026, suppliers must repair faulty smart meters within 90 days or face Ofgem enforcement action. This applies to core meter functionality — in-home displays are explicitly excluded from this requirement.
• £40 automatic compensation: Effective 23 February 2026, Guaranteed Standards now require suppliers to automatically pay £40 when smart meter-related issues breach prescribed timeframes.
• Annual submission requirements: Suppliers must submit annual plans to Ofgem detailing their smart meter installation schedules and functionality targets as part of the 2030 rollout commitment.
• 2G/3G replacement mandate: The government requires suppliers to replace 2G and 3G smart meters before the 2033 network shutdown, ensuring continuity of service for customers with older device models.
• Government review outcome: A smart meter review launched in August 2025 published its findings on 10 March 2026, informing the new regulatory standards now in effect.

The implication is that suppliers who previously left smart meter faults unresolved now risk automatic financial penalties, fundamentally shifting the cost-benefit calculation around meter maintenance.

Suppliers will have up to 90 days to fix your faulty smart meter or face legal action. — Emily White, MoneySavingExpert

Under tough new standards, suppliers will have no more than 90 days to repair faulty smart meters – or else face action from the regulator. — GOV.UK (Government statement)

Ofgem’s review found 34,000 have been overcharged by suppliers such as Octopus Energy, Ovo Energy and Utility Warehouse. — MoneyWeek

The pattern emerging from these overcharge cases is clear: as energy suppliers have scaled rapidly, billing infrastructure hasn’t always kept pace. For UK customers, the regulatory response — mandatory refunds, automatic compensation, and hard repair deadlines — represents a meaningful shift in consumer protection. For Irish customers, the gap in published data makes it harder to assess whether similar protections are needed or in place. The implication for anyone reviewing old energy bills is straightforward: billing errors happen, but the mechanisms to recover your money have never been stronger.