Latest figures show RPI in Guernsey has fallen to 5.1% which means it's significantly higher than the rate in Britain and above Jersey's current rate.
Inflation in Guernsey dipped by just 0.2% in the three months between June 2024 and September.
It takes the figure to 5.1%, which is triple the UK rate and above Jersey's RPI figure of 5%.
Housing costs, such as mortgages, rent and home insurance, contributed the most to keeping the costs of living in Guernsey high.
The household services category, which measures the price of things like broadband connections, phone charges and the cost of using cleaners and childminders was also relatively high.
RPIX, which is inflation minus mortgage payments, was running at 4.4% in the three months to the end of September 2024.
Inflation in Guernsey is reducing, for instance, RPI was nearly 2% higher one year ago.
Commenting at the end of the last quarter's figures, economist Richard Hemans from the Institute of Directors warned that housing costs were continuing to keep inflation high, which could be problematic:
"The island is an attractive place to live and work, and the supply of housing and labour remains very tight. The States of Guernsey’s focus on providing more housing is exactly right because it will have both long-term economic and social benefits.
Guernsey’s rate of inflation is stubbornly high, which could undermine our competitiveness if not addressed."