The property search site said that confidence among sellers has been seriously dampened by the outcome of the Brexit vote.
London prices, which were already looking the most overvalued, have been hit the hardest, falling 1.1% in just one month.
The average house price in the South East also slipped 0.2% during the last month, but the biggest drop outside London was in the North East (-0.7%).
This fall comes as a serious blow to a region that was just showing the first signs of genuine recovery since the financial crisis sent the market into a downward spiral.
However, several English regions and Wales still indicate price growth. The East Midlands rose the most (0.7%) over the last month, followed by the North West (0.4%), Wales (0.4%), Yorkshire (0.3%), the West Midlands (0.2%) and the East of England (0.1%).
As the Brexit vote is only two weeks old, we may well see these figures turn negative next month.
Doug Shephard, director at Home.co.uk, said: “It is too early to fully appreciate the Brexit fallout for the UK property market but the initial indications are certainly worrying.
“The foreign exchange markets and stock exchanges reacted quickly, sending the pound’s value downwards; the share values of homebuilders down dramatically; and, as this Index shows, the value of residential property in the UK is also now falling.
“The referendum result has certainly unnerved many investors, so much so that seven commercial property investment funds have been closed and the Financial Conduct Authority forced to step in with guidance. Residential property investment has also been hit, with homebuilders losing over 30% of their share value.
“Expect both consumer and investment decisions to be delayed until there is somewhat less uncertainty about future prospects for the UK economy; unfortunately, however, uncertainty looks set to remain for some time. While continued weakness in the pound should help the exports of some companies, we cannot export our houses.
“Until last month, the property market had been functioning well and was helping to shore up the fragile UK economy. Brexit just knocked off one of the wheels.”