Would-be tenants searching for their ideal home on the internet have a one in three chance of being disappointed because the property they would like to rent has already been let.

This is the key finding of research carried out by online property rental specialist upad.co.uk who claim that letting agents are uploading their entire stock to portals, which results in tenants having a bad experience.

A sample taken from four of the major property portals identified a total of 146 properties repeated on the same website, and 323 that were no longer available to be let.

James Davis, founder of upad, said: “Hunting for somewhere new to live is stressful enough, so it is worrying to see that anyone doing an online search in the UK has a one in three chance of receiving details of a property that has already been let.

“This wastes time and causes disappointment and frustration – it is also completely unnecessary. Agents are clearly uploading their entire stock to the portals, and this is giving users a bad experience.

“Travel and recruitment websites, for example, have harnessed the web to ensure they offer customers an up-to-date and relevant service. Isn’t it time the online property rentals industry also moved into the 21st Century?”

When it comes to finding property to rent, people often identify with websites that display out-of-date information, and offer a poor online experience.

Research shows that 83 percent of UK internet users are unhappy with their property search experience (FindsYou.com 2008 research), and 39 percent of renters state that out-of-date information has been the biggest problem when looking for rental property (rentright.co.uk 2007 survey).

Upad, a free online rentals service, claims its site is rigorously checked to ensure data it not duplicated and is up-to-date.