The change in price, which will come into force from 24th February, will affect around 59,000 customers.
The increase will add £5.95 a week to the average household bills.
Customers with a credit meter are expected to see the annual gas bill rise by about £325 a year to £1,293.
For those customers with prepayment gas meter costs will increase by around £309 per year to £1,230.
Raymond Gormley, Head of Energy Policy at the Consumer Council said: “The Utility Regulator forewarned us that energy price rises of this nature will continue because of exceptionally high global wholesale gas prices, however, it is never good news for consumers when prices go up.
“With the cost of energy continuing to increase, the Consumer Council is concerned about a potential rise in fuel poverty as many families may struggle to find the extra money they will now need to pay for heating.”