Gas Supply Emergencies: Warnings, Deficit Notices and Household Priority

A gas supply emergency in Britain escalates in stages: early notices to the market when the margin between supply and demand tightens, then firmer measures that curtail large users before anyone else, and only in the most severe stage a network gas supply emergency in which households themselves are at risk. Domestic customers sit last in that order, because the framework is built to protect homes, hospitals and other protected sites for as long as the physics of the network allows. A request to stop using gas is an appeal to lower demand, not a disconnection at your meter.

The context matters for judging how real that risk is. Gas demand in the UK in 2024 was 687 terawatt hours (TWh), which is 37% lower than demand in 2010 and the lowest level since the early 90s¹. But the UK is a net importer of natural gas, importing more than it exports, which makes it vulnerable to global price volatility². In a typical recent five-year period, the UK Continental Shelf provided 43% of gross annual gas supply and the Norwegian Continental Shelf 35%³. Shortage, in other words, is a tail risk; price spikes driven by events elsewhere are the everyday exposure.

In brief: a phased sequence, homes at the end

The emergency framework is a ladder, and each rung exists so that the rungs above it are never needed. At the bottom are informational notices: signals from the system operator that the margin between gas flowing into the network and gas being drawn out is tighter than comfortable. These go to the market, not to households, and their purpose is to prompt shippers and suppliers to bring more gas forward, from storage, from imports or from flexible production. If the margin tightens further, the notices sharpen into deficit warnings, which state explicitly that supply is likely to fall short of demand and that the market must respond.

If the market response is not enough, the framework moves from information to action, and the action is curtailment in a fixed order. Large industrial users who can tolerate interruption, or who have alternative fuels, are curtailed first, because interrupting them protects the greatest number of people for the least harm. Power stations and other users follow. Domestic customers are last, and within the domestic category the framework does not distinguish between households: the protection is physical, not means-tested. A household's gas is not switched off at the meter while a factory down the road keeps running.

The top of the ladder is the network gas supply emergency, the stage at which pressure in parts of the network can no longer be maintained and areas may lose supply physically. Even here the order holds: protected sites, including hospitals and other safety-critical loads, are maintained for as long as possible. Restoration then works back down the ladder, with large users reconnected first and households as pressure allows. If you want to understand who physically delivers gas to your street and who you would contact in an emergency, see gas distribution networks; if you smell gas, the immediate steps are on what to do if you smell gas in your home.

The numbers underpinning the scheme

The scale of the system the framework protects is large but shrinking. The 687 TWh of gas demanded across the UK in 2024 was the lowest since the early 90s¹, a fall driven partly by efficiency and partly by the decline of gas in electricity generation. On the household side, the average GB home uses 13,697 kWh of gas a year⁴, and there are around 16 million gas meters in the UK⁵. That is the base the curtailment order is designed to protect: tens of millions of people whose heating and hot water depend on the network holding pressure.

The supply side is where the vulnerability sits. The UK is a net importer of natural gas², with the UK Continental Shelf providing 43% and the Norwegian Continental Shelf 35% of gross annual supply on a five-year average³. The remainder arrives as imports, through pipelines and as liquefied natural gas, which is why the framework's early stages are aimed at the market: much of the gas that would fix a deficit has to be attracted from elsewhere, and price is the signal that attracts it. The mechanics of that trading are covered in how the wholesale gas and electricity markets work and where Britain's gas comes from.

The price dimension is inseparable from the emergency framework, because a deficit is usually visible in prices before it is visible in physical supply. The energy price cap for an average dual fuel Direct Debit household was £531 (22%) lower in 2025 than at the height of the energy crisis at the start of 2023, when the Energy Price Guarantee was in place⁶. Cap changes track real costs: Ofgem attributed a later rise to increases in the costs of transporting energy in Great Britain and in government schemes and essential support⁷. For households, the practical lesson is that the framework protects the flow of gas; it does not protect its price.

Causes of insufficient supply

A gas deficit is never caused by one thing. The events of the 2022 price crisis illustrate the combination: the return of global gas demand after pandemic restrictions, high demand from cold weather, supply unable to keep up, regional factors in Europe, debate about whether Gazprom could increase supply, low levels of wind, outages at nuclear plants, and a fire that shut down a key electricity interconnector². Several of those are electricity-side factors, and that is not a mistake: when power stations cannot generate, gas-fired generation is called on more heavily, which tightens the gas system at the same moment the weather is tightening demand for heating.

Cold weather is the classic driver, because domestic heating is the least flexible part of gas demand. Heating our homes accounts for around 14% of the UK's total greenhouse gas emissions⁸, a figure that reflects how much of the nation's gas burn sits in households, the very category the curtailment order protects last. A cold snap raises that burn sharply, and unlike a factory, a household cannot switch to an alternative fuel at short notice. This is why the framework's early stages lean so hard on the market and on large users: the household end of the system has almost no elasticity to call on.

The electricity system's dependence on gas adds a second layer. The Climate Change Committee has factored in a 50% increase in demand on electricity, to reflect the expected increase from the decarbonisation of transport, industry and buildings⁹. As heating and transport electrify, shocks that once hit the gas system increasingly hit both systems at once, which is why the gas emergency framework and the electricity margin framework, covered in electricity margins, shortfall notices and the risk of shortages, are designed to be read together. The winter outlooks that assess these risks are explained in the NESO winter and summer outlooks.

How the scheme varies across the four UK nations

The gas emergency framework itself operates on a GB basis, but the exposure behind it differs across the nations, and some of the household-level rules that sit around it differ sharply. On exposure: the UK as a whole is a net importer of natural gas², and the supply shares, 43% from the UK Continental Shelf and 35% from the Norwegian Continental Shelf³, describe the whole country's position. Scotland's production, Wales's network and Northern Ireland's separate arrangements are covered in energy supply in Scotland, energy supply in Wales and energy supply in Northern Ireland.

Where the nations genuinely diverge is in the safety and standards rules that apply to gas in the home, which are the rules a household actually encounters day to day:

• England: from 1 October 2022, all relevant landlords must provide a carbon monoxide alarm in any room used as living accommodation which contains a fixed combustion appliance, excluding gas cookers¹⁰.
• Wales: the Fitness for Human Habitation Regulations require a landlord to ensure a carbon monoxide alarm is present in any room which has a gas, oil or solid fuel burning appliance installed¹¹.
• Northern Ireland: the Building Regulations (Northern Ireland) 2012 treat the provision of devices to detect and give warning of the presence of carbon monoxide gas in a dwelling as exempt from notices and deposit of plans¹².
• England only: Boiler Plus additional minimum standards came into force from April 2018 in England only¹³, and they require existing households to install an additional energy saving measure from a choice list at the point of installing a new or replacement combi gas boiler in an existing dwelling¹⁴.
• Wales, proposed: the proposed standard would make timers and room thermostats an explicit requirement for all gas and oil systems¹³.

The lesson for a household is that the emergency framework is national, but the protections around your own gas appliances are not. A carbon monoxide alarm is a legal duty on your landlord in England and Wales, and a practical necessity everywhere, because a supply emergency is not the only way gas becomes dangerous in a home. Faults and low pressure have their own pages: what to do about low gas pressure and what to do if your gas appliance is faulty.

Regulations running in parallel with the emergency

Beyond the emergency ladder itself, a body of licence conditions and regulations shapes how suppliers and networks must treat households when the system is under stress. Ofgem publishes a licence guide for consumers, which it describes as "intended as a helpful tool only, and does not modify or replace the conditions in the gas and electricity supply licences"¹⁵. The licences themselves carry the force: they govern what a supplier must do for customers in debt, in difficulty and in an emergency, and Ofgem has pressed suppliers on debt after finding customers accruing more unpaid bills, with average gas debts at individual suppliers including £911 at Utility Warehouse and £831 at npower¹⁶.

Several specific rules bear on the household side of a gas emergency:

• Standing charge tariffs: Ofgem has consulted on a requirement to offer lower standing charge tariffs, with a reduction of £85 to £100 for gas consumers, broadly reflecting the ratio of non "pass through" costs in the cap¹⁷.
• Energy Performance of Buildings Regulations 2012: a penalty charge notice of £200 applies for a dwelling in connection with missing energy performance documentation¹⁸.
• Warm Home Discount (England and Wales) Regulations 2022: a supplier may not count the costs of installing a mains gas fuelled boiler or central heating system under the scheme unless it replaces an existing mains gas system and at least one person in the premises is aged 65 or over, under compulsory school age, or has significant health problems or a disability making them vulnerable to cold-related illness¹⁹.
• F-gas regulations: fluorinated gas rules passed into UK law in 2015¹⁴, with enforcement of the GB F gas Regulation the responsibility of the Environment Agency in England.
• Micro business data: gas supply licence condition 41 prohibits the licensee from obtaining Gas Consumption Data relating to a period of less than one month at micro business premises, subject to exceptions²⁰.

The Energy Price Guarantee also had a legislative anchor: a clause introduced in 2022 introduced Schedule 3 modifying the Domestic Gas and Electricity (Tariff Cap) Act 2018 to support the operation of the energy price guarantee in Great Britain²¹. That episode is the clearest demonstration of how far the rules can bend in a crisis: when wholesale prices overwhelmed the cap in 2022, Parliament modified the cap's own legal basis to keep household bills bounded. The framework for physical emergencies is designed with the same instinct, protecting the household first and the market's normal operation second.

The impact on a home's energy self sufficiency

The honest reading of the framework is that it protects a household's gas supply while leaving the household dependent on gas. The UK has been strongly affected by the energy crisis due to its dependence on natural gas for heating, electricity generation and industry²², and the government's own Spring Statement described the UK as "a net energy importer with a high dependence on gas and oil"²³. A home on the gas network is protected from physical curtailment, but not from the price of the gas it burns, and not from the global events that move that price, which are traced in how global events move UK energy prices.

History shows how much of a household bill is set by gas rather than by policy. The Committee on Climate Change found in 2011 that household energy bill increases were caused primarily by the rising cost of gas, with support for investment in low-carbon power capacity contributing £100 to the projected increase for a dual-fuel household²⁴. UK climate action has since reduced emissions without increases in household energy bills²⁵, and business gas prices have been lower than those in comparable European countries²⁵. The volatility, though, is structural: gas prices at UK delivery points rose 30.9% year on year as early as 2013²⁶, long before the recent crisis, and domestic margins in the retail market have been watched closely since, with British Gas reporting a 7.0% domestic combined gas and electricity EBIT margin in 2015²⁷.

Reducing a home's exposure therefore means reducing its gas use, and the policy picture there is mixed. The Climate Change Committee has judged that the policies needed to drive improvements in energy efficiency in homes that are not fuel poor are currently inadequate²⁸, and has called for incentives to act and greater awareness of preparing for climate risk²⁹. Meanwhile the system around the home is changing: emissions continue to fall, with provisional 2025 emissions of 366.6 MtCO2e, 54% lower than 1990 excluding international aviation and shipping³⁰, and final 2024 emissions of 415 MtCO2e including them³⁰. Each home that insulates, electrifies or generates its own heat moves a little further out from under the emergency framework, because it no longer needs the ladder to be climbed correctly on its behalf.

For the households that remain on the network, the practical protections are real but bounded:

• Physical supply: protected last in the curtailment order, and restored as pressure allows.
• Price: not protected by the emergency framework; the price cap and, in extremis, legislation like the Energy Price Guarantee are the instruments for that.
• Safety: covered by separate rules, including landlord carbon monoxide alarm duties in England and Wales¹⁰.
• Debt and vulnerability: covered by supplier licence conditions and Ofgem enforcement, not by the emergency ladder¹⁵.

The full picture of what a household can control, from insulation to flexibility to generation, is set out in energy security and household independence. The gas emergency framework is the backstop for the homes that cannot yet do without it, and the number of those homes, 16 million gas meters⁵, is the measure of how much work remains.