On a quarterly basis, prices grew 2.4 per cent, lower than June's 3.3 per cent, while the monthly figure fell by 0.6 per cent - its first drop since February this year.
The figure suggests there may still be a hangover from the General Election, when house buyers held off over concerns about the future of stamp duty - and in the capital, a potential mansion tax.
Stephen Smith, director of Legal & General Mortgage Club, suggested July's fall in growth is likely to be a blip.
"We don’t expect this trend to last. Strong market conditions, driven by low inflation and rising wages, along with the monetary policy committee's recent hints of rate rises, are likely to drive more people to the market in the remainder of the year."
But there were also concerns market conditions will continue to hit those at the bottom end of the market.
"The upside for housing market activity and prices is expected to constrained by more stretched house prices to earnings ratios, tighter checking of prospective mortgage borrowers by lenders and the likelihood that interest rates will soon start rising gradually," said Howard Archer, chief European economist at IHS.
"Indeed, mortgage lenders have already started to withdraw some of their lowest mortgage rates. At least though, the Bank of England is stressing that interest rates will only rise gradually and to a limited extent."