Your gross household income must be less than £80,000 per annum (outside of London) and you must be unable to afford to purchase a home on the open market without financial help. Generally you should be a first time buyer, and not own a home or land, or have a financial interest in a home or land in the U.K. or abroad.
Current shared home owners may be considered again for shared ownership if they have an approved application with the Help to Buy Agent, cannot afford to purchase a suitable property on the open market, and meet the scheme and property criteria. Catalyst also require that your current home must be for sale - or in the case of purchasing a re-sale property, your current home should be sold with a confirmed exchange or completion date from your solicitor. As well as all of the above requirements for current shared owners, other current home owners must have written support from their local authority.
You will have to be able to afford low cost home ownership in the long term and will have an affordability assessment carried out to ensure it is affordable for you.