Here are some links that you might find useful:
The Association of Independent Inventory Clerks
The AIIC are dedicated to promoting the highest possible standards of accuracy and reliability and have been endorsing high levels of professionalism in the inventory business since 1996.
The Association of Residential Lettings Agents ARLA
The Association of Residential Letting Agents, is the only professional self-regulating body to be solely concerned with lettings.
Deposit Protection Service (DPS)
The Deposit Protection Service (DPS) is open to all landlords and letting agents, and is the only scheme that is free to use.
MyDeposits
MyDeposits is an insurance-based deposit protection scheme for Agents and Landlords which is simple to use and pay-as-you-go.
The Dispute Service (TDS)
The Dispute Service (TDS) is an independent, not-for-profit company established in 2003 to resolve complaints and disputes arising in the private rented sector.