From 6 April 2007, all deposits taken by landlords and letting agents under Assured Shorthold Tenancies (ASTs) in England and Wales must be protected by a tenancy deposit protection scheme. Landlords and letting agents must not take a deposit unless it is dealt with under a tenancy deposit scheme.

To avoid any disputes going to court, each scheme will be supported by an alternative dispute resolution service (ADR). Landlords and letting agents will be able to choose between two types of scheme; a single custodial scheme and two insurance-based schemes.

You can learn more on the government website, which includes an overview of the requirements, and also links to the sites of the companies running the various schemes:

More info go to: Direct Gov Info