Important terms: SPC, EAC and tariffs

The terms here are important to understand in advance of connecting to natural gas as they could affect your bill.

​Non Daily Metered customers

This information relates to Non Daily Metered customers only. Non Daily Metered customers have an annual energy consumption of less than 5,550,000 kWh and their meters are read monthly or bi-monthly.

Estimated Annual Consumption (EAC)

You will be asked to provide your Estimated Annual Consumption (EAC). This figure will be in kilowatt hours (kWh) and is the best estimate of the amount of natural gas your business will consume in any given year. This estimate can be based on your previous fuel consumption (if you are switching from another fuel) or your predicted annual fuel consumption if the connection is for a new development. This estimate for annual consumption of natural gas is based on the types and numbers of appliances being used (e.g. boilers, cookers, fryers, tumble dryers, air conditioning etc) and on the number of hours and days per year that these appliances are operating.

Supply Point Capacity (SPC)

Gas Networks Ireland owns and operates the natural gas network in Ireland, transporting natural gas around the country on behalf of licensed natural gas suppliers. These licensed natural gas suppliers are required to reserve "space" in the natural gas network to guarantee a secure supply to each of their customers. The amount of space reserved by gas suppliers for each customer is referred to as the Supply Point Capacity (SPC). Gas Networks Ireland charges all natural gas suppliers for reserving this capacity on the network and will guarantee gas supply to match the customers 'peak day' demand level.

The charge is agreed with the Commission for Regulation of Utilities (CRU) and is reviewed annually. It is therefore important to provide a realistic EAC to ensure that an appropriate Supply Point Capacity is set for your business, as this will ultimately affect the initial costs payable by you to your chosen gas supplier in monthly standing/ supply charges. The SPC for each customer is reviewed and updated annually based on the customer's actual natural gas usage, measured in kilowatt hours. The natural gas year begins on October 1st and ends on September 30th. Thus the revised SPC comes into effect on the first day of October every year.


There are a number of tariffs which apply in the natural gas market, including (for NDM Customers) Small Business User, Medium Business User and Fuel Variation Tariff. Business customers are automatically allocated to their appropriate tariff by natural gas suppliers depending on SPC and annual gas usage levels, and customers are billed for gas usage on a monthly / bi-monthly basis.

Existing customers

Customers that wish to review their current tariff, SPC or EAC should engage with their current gas supplier. Details of suppliers can be found on the Commission for Regulation of Utilities (CRU) website.