Getty ImagesUK inflation fell unexpectedly to 1.7% in the year to September, the lowest rate in three-and-a-half years.
It means the annual rate prices are rising at is now below the Bank of England's 2% target, paving the way for further interest rate cuts.
Lower airfares and petrol prices were the main drivers behind the surprise slowdown, official figures showed.
Separately, September's inflation figure is also normally used to set how much many benefits rise next April.
Surprise fall in inflation paves way for interest rate cuts
