Greater Belfast’s Cheapest Offer* for Domestic Credit Customers: Based on customers on the firmus energy Greater Belfast Home Gas Tariff – Credit Meter Online with introductory 32% discount applied in comparison to the SSE Airtricity Tariff - Direct Debit Budget Plan. The Welcome Discount offer is subject to a 12-month contract*.
Customers who avail of this introductory offer will see a 32% discount off the standard Greater Belfast Home Gas Tariff – Credit Meter Online as a separate line on their bill. Contact us and we will be happy to talk you through our rates, the 32% Welcome Discount (Domestic)* or any queries that you may have. Correct as of 15/05/2026. Verify at Cheapest Offer* New customer offer only, terms and conditions apply 32% Welcome Discount (Domestic) T&Cs*.

Greater Belfast’s Cheapest Offer** for the average firmus Domestic PAYG (Pay As You Go) Customer: Based on customers with an annual consumption of 7,734 kWh**, or lower, calculated using a firmus energy effective unit rate, in comparison to the SSE Airtricity Tariff – Prepayment Meter Pay As You Go. The Welcome Bonus offer is subject to a 12-month contract**. The effective unit rate is calculated using annual consumption of 7,734 kWh** at the firmus energy Greater Belfast Home Gas (PAYG) Tariff with £275.00 Welcome Bonus applied. Customers who use more or less than 7,734 kWh** per year will not receive the firmus energy effective unit rate. If your annual usage is above this, it may not be the cheapest offer and for any customer using 12,545 kWh or more per year this is not the cheapest offer. Actual average consumption varies due to weather conditions, changes in energy efficiency and householder behaviour. Contact us and we will be happy to talk you through our rates, the Welcome Bonus or any queries that you may have. Correct as of 15/05/2026. Verify at Cheapest Offer**. New customer offer only, terms and conditions apply £275 Welcome Bonus T&Cs.** 7,734 kWh is the firmus energy average annual consumption for customers with a Pay As You Go meter in the Greater Belfast area.

TrustScore 4.9/5. Showing 5-star reviews. These testimonials represent each customer’s own experience regarding firmus energy and may not be representative of all firmus energy customers.

†Savings tips sourced from:

https://energysavingtrust.org.uk/advice/thermostats-and-heating-controls/,

https://www.nidirect.gov.uk/articles/energy-efficiency-tips and

https://energysavingtrust.org.uk/advice/boilers/