Jersey's Retail Price Index, which measures the average changes in goods and services, hit 10.4% in September.
RPI has risen from 7.9% in June.
It's the greatest jump in the cost of living since September 1990.
The costs of energy and housing were the biggest factors in the hike.
The cost of borrowing increased sharply following the outgoing Prime Minister's mini budget which spooked the financial markets and spiked mortgage rates.
Food prices and the cost of motoring have had a huge effect on the rise.
In June, public transport fares saw a dip of 2%, but have since jumped nearly 9%.
The UK's inflation rate hit 10.1% in September.
New website helps children and families navigate the digital world
More time in Jersey for French day-trippers
Rapist jailed more than two decades after his crime
Jersey Airport to see 20,000 passengers in the run up to Christmas
Both winning CI Christmas Lottery Tickets sold in Jersey
Jersey churches host free Christmas events in the Royal Square
Support service set up for carers of people with mental illness
New Jersey Opera House CEO appointed
