Thanks for registering your interest in switching your gas to firmus energy
Our team has received your enquiry and will be in touch shortly.
In the meantime if you would like to contact our Customer Enquiry Team please call 0330 024 9000.
Switch and Get the Cheapest Gas Offer in Greater Belfast*
Credit Meter
Offer
- Save 20% when you switch*
- Cheapest* Gas Offer in Greater Belfast
- Flexible bill payment options
- Access your account 24/7
Pay As You Go
Offer
- Enjoy £200 welcome bonus**
- Best PAYG gas offer**
- Easily manage your costs
- Only pay for what you use
Why choose
firmus energy?
Great Savings for Customers - Enjoy our best value rates
Hassle-Free Switching - We handle the process for you
No Interruption to Your Supply - Just great service & a smooth switch
Trusted by Thousands - Heating homes across Northern Ireland
Friendly, Reliable Service - Contact us by phone or email, 5 days a week
Greater Belfast’s Cheapest Credit Offer* for the Average Customer: Comparison is based on effective unit rates which include all supplier discounts in Belfast, with effect from 1st November 2025, and calculated using the Ofgem average domestic usage of 12,000kWh. Customers obtain firmus energy’s effective unit with an average consumption of up to 12,500kWh. If your annual usage is above this, it is not the cheapest unit rate. 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 20% Welcome Discount (Domestic)* or any queries that you may have. Correct as of 16/10/2025. Verify at Cheapest Credit Offer*. New customer offer only, terms and conditions apply 20% Welcome Discount (Domestic)* T&Cs.
Greater Belfast’s Best PAYG Offer** for the Average Customer: Comparison is based on effective unit rates which include all supplier discounts and welcome credit in Belfast, effective from 1st November 2025, and calculated using the Ofgem average domestic usage of 12,000kWh. Customers obtain firmus energy’s effective unit with an average consumption of up to 12,000kWh. If your annual usage is above this, it is not the best unit rate. 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 16/10/2025. Verify at Best PAYG Offer**. New customer offer only, terms and conditions apply £200 Welcome Bonus** T&Cs.