Regulated gas goes up 19.2% in Greater Belfast and the West on 1 October, and 9% in the Ten Towns. Both cover small businesses, not just homes.

Reacting to: Increase to Firmus Energy Supply’s regulated gas tariff and reminder to consumers on support available (Utility Regulator, 4 September 2026) →

Two tariff decisions landed a week apart. On 28 August the Utility Regulator confirmed that SSE Airtricity Gas Supply’s regulated tariff would rise by 19.2%, or £174 a year, in the Greater Belfast and Gas to the West areas. On 4 September it confirmed that firmus energy’s regulated tariff in the Ten Towns would rise by 9%, or around £87 a year. Both take effect on 1 October 2026.

Almost all of the coverage has treated this as a household story. Read either announcement and the same phrase appears in the regulator’s own words: the tariff it reviews is the tariff “for domestic and small business customers”. That is the part worth stopping on. If you run a café, a salon, a bakery, a small workshop or an office and you buy gas on a published tariff rather than a contract you negotiated, this is your cost line moving, three weeks from now, by a percentage you had no say in.

What the Utility Regulator actually decided

The SSE Airtricity review covers around 203,500 customers in the Greater Belfast area and around 5,500 in the Gas to the West area. The firmus review covers 76,863 customers in the Ten Towns. That is roughly 286,000 accounts across Northern Ireland, and the small business share of them is not a rounding error.

The regulator is clear about the cause, and it is not supplier margin. Markets Director Colin Broomfield put the wholesale price of gas at 169 pence a therm in late August, “twice as high as pre-conflict prices”. A week later, in the firmus announcement, Leigh Greer put it at around £1.80 a therm, having doubled since the Iranian conflict began. The regulator also notes that regulated suppliers’ profits are capped at around 2%. The money is going to the wholesale market, not to the supplier.

For context, here is the regulator’s own comparison of combined annual regulated electricity and gas bills from 1 October, on 3,200 kWh of electricity and 12,000 kWh of gas:

Northern Ireland stays below both. But those are household consumption figures on a standard credit tariff, and the regulator flags that the Great Britain number already includes VAT and policy cost reductions that have not yet been applied here. Being 4% below a cap is not much comfort when your own bill has just moved by a fifth.

Why two businesses 25 miles apart get different increases

This is the bit that is genuinely ours and nowhere else’s. Northern Ireland does not have one gas market. It has two, with different distribution network operators and different network use of system costs, which is exactly why one week produced 19.2% and the next produced 9%.

The Greater Belfast area runs from North, South, East and West Belfast out through Carrickfergus, Newtownabbey, Lisburn, Carryduff, Castlereagh, Ballygowan, Newtownards, Larne and North Down. The Western area is Enniskillen, Cookstown, Magherafelt, Omagh, Dungannon and Strabane. The Ten Towns area is Derry/Londonderry, Limavady, Coleraine, Ballymoney, Ballymena, Antrim, Craigavon, Banbridge, Newry, Armagh and more than 25 other towns and villages.

So a bakery in Dungannon and a bakery in Portadown, forty minutes apart, get a different increase on the same morning because of which pipe network their postcode sits on. One more wrinkle worth knowing: the regulator states plainly that it does not regulate firmus energy’s Greater Belfast tariff. A firmus customer in Belfast is not covered by the Ten Towns decision at all. If you assumed your supplier’s name told you which announcement applies to you, it does not.

An illustration: the same café in Omagh and in Portadown

Built from the published percentages and published tax rules, not from a client file. Take a small café using 60,000 kWh of gas a year — 5,000 kWh a month — and spending £4,200 a year on gas before VAT.

£428 a year of pure geography between two identical businesses. And because the increase is a deductible cost, a limited company paying corporation tax at the 19% small profits rate — the rate on profits up to £50,000 — carries £653 of the Omagh café’s £806 after tax relief. Real money, but less than the headline, and it only helps if the business is profitable enough to get the relief.

The VAT line most small businesses get wrong

Whether you pay 5% or 20% VAT on business energy turns on how much you use, not on what kind of business you are. HMRC’s VAT Notice 701/19 sets the de minimis limits: piped gas is reduced-rated at 5% where the supply to one customer at one premises is no more than 150 therms or 4,397 kWh a month, and electricity at 5% where it is no more than 1,000 kWh a month. Above those, it is standard-rated at 20% unless at least 60% of the supply is for qualifying use.

Our illustrative café burns 5,000 kWh a month, so it sits just over the gas line and pays 20%. A smaller unit next door burning 4,000 kWh pays 5%. If you are VAT-registered, either rate is recoverable and the increase costs you the net figure. If your turnover is under the £90,000 registration threshold, you carry the VAT as well — which is the group this increase hits hardest.

There is a second line on a business gas bill that a household never sees. The Climate Change Levy runs at 0.801p per kWh for gas from 1 April 2026, rising to 0.827p from 1 April 2027, and HMRC states the rates do not apply to supplies to domestic consumers or to charities for non-business use. On 60,000 kWh that is £481 a year, separate from the tariff and unaffected by it. Worth knowing it is on the bill before you go looking for the increase in the wrong row.

Two things to do this week

Confirm which gas area and which tariff you are actually on. Not the supplier name — the area, and whether you are on the regulated tariff or a contract. Your last bill says it. The Utility Regulator’s business consumers page sets out what protections apply to a non-domestic account, and its guide to managing energy debt is the right first call if the October bill is going to be a problem rather than an annoyance.

Reforecast from 1 October, not from your year end. Take the percentage, apply it to your actual gas spend, and put the new number into the cashflow for the winter quarter — that is when the volume is highest and the increase bites hardest. That is ordinary management accounts and cashflow work, and it is a great deal cheaper than finding out in February. While you are in the bill, check your monthly kWh against the 4,397 line and make sure the VAT rate on it is right, which is a VAT returns question worth asking once rather than never.

What is still uncertain, and when we will know

Three open questions, and it is worth being precise about which is which. Electricity. Power NI’s domestic tariff was not part of this review, and the regulator says only that it continues to monitor it — so there is no electricity decision to plan around yet. The discount. The Department for the Economy said on 25 August that a VAT reduction worth “over £50” would be added to the NIRO Domestic Electricity Discount Scheme, with the combined discount now proposed for October rather than September. The regulator’s own footnote says the funding is still to be confirmed by Treasury and the final figures and dates are not settled. It is also a domestic scheme, so no business should put it in a forecast. Wholesale. At £1.80 a therm the price is roughly double where it sat before the conflict; where it goes next decides the next review, and these tariffs are typically revisited around April.

What is not uncertain is the date. On 1 October the rate changes, and the businesses that notice in October will handle it better than the ones that notice in January. If you want your winter numbers looked at with the new rate in them, that is what our Northern Ireland team does from the office in Ballymena — and the business rates guide covers the other fixed cost that lands on the same premises.