Switch and Get the Cheapest Gas offer in Greater Belfast**
Credit Meter Offer
or find out How It Works
How It Works
There are 4 easy steps to switch:
-
1
Getting Started
What you will need:
Bank Details: Including sort code and account number. These can be found on your bank statement or cheque book.
SMP Number: This can usually be found at the top right-hand corner of your bill. If you don't have a copy of your bill, simply call our Switch Team on 0330 024 9000 and they can help you. -
2
Switching Your Home
We will contact your current gas supplier on your behalf and keep you updated by letter or email. You have ten working days from the date you submitted your online application to cancel.
-
3
Your Switch Date
Your switch date is usually 5-6 weeks from the date we receive your application online or by phone. You will receive a letter confirming the date that you will become a firmus energy customer.
-
4
Welcome to firmus energy
What happens next?
You will receive your firmus energy welcome pack and notification of your Direct Debit instructions. Finally, sit back and enjoy cheaper natural gas from firmus energy!
- 32%* off Gas for New Customers
- Cheapest credit meter offer*
- Hassle free switching
- Flexible bill payment options
- Access your account 24/7
- No Interruption to Your Supply
- Trusted by 130,000 Homes
- Enjoy Local Customer Support
- Rated 4.9 on Trustpilot
Pay As You Go Offer
or find out How It Works
How It Works
There are 4 easy steps to switch:
-
1
Getting Started
Your Meter Module Number:
this can be found on your meter.
Your Meter Serial Number: this can also be found on your meter and can start with an ‘E’, 'S' or an 'I'.
e.g. E6 S00123456789. -
2
Switching Your House
We will contact your current gas supplier. We'll send you a letter or email to keep you up to date. You have 10 working days from the date you submitted your application online to cancel.
-
3
Your Switch Date
Your switch date is usually 5-6 weeks from the date we receive your application online or on the phone. You will receive a letter confirming the date that you will become a firmus energy customer.
-
4
Welcome!
What happens next?
We will write to you to confirm you are a firmus energy customer and the steps you need to carry out to update our tariff on your meter. If you have a blue PAYG card we will send you a new firmus energy card.
- Enjoy £275 welcome bonus**
- Cheapest PAYG gas offer**
- Easily manage your costs
- Only pay for what you use
- Hassle-Free Switching
- No Interruption to Your Supply
- Trusted by Thousands
- Friendly, Reliable Service
- No more bills
Offline Belfast Credit Meter
Paying by Direct Debit is optional with the offline tariff however if you do, you will receive a discount of £22.05 per annum.
Connect NowNot connected to natural gas yet?
Phoenix Natural Gas, owns, operates and develops the natural gas network throughout the Greater Belfast area. firmus energy have a licence within this area to supply natural gas. Please contact a member of Phoenix's connection team to discuss your options 03454 55 55 55.
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
