The number of properties sold fell by 5.5% compared to August and by 0.5% compared to the same month last year.
The index shows significant regional variation, with the number of sold properties in Scotland up 10.0% in September compared to the previous month, and up 6.2% in the East Midlands.
London, however, saw the greatest monthly fall, with the number of sold properties down 22.1% on August’s figure. The North-East also registered a large fall, of 18.3%.
In terms of for-sale listings, the West Midlands saw a 3.1% rise and Scotland saw a 2.4% increase, but Wales experienced a fall of 22.3% and the North West was down 14.9%.
Stephen Watson, managing director at Agency Express, says: “At first glance these figures might appear a little disappointing, but take a closer look and they reveal some encouraging, positive signs, with many regions and individual cities bucking the seasonal trend.
“There appears to be consensus across most of the property-related indexes that the UK housing market is still facing challenges amid economic uncertainty, both at home and abroad, but it is important to recognise the progress that has been made since the market lows experienced in 2008 and that it’s not all doom and gloom.”