Adult children or other relatives or friends who live in your home as part of your household are called 'non-dependants'. This does not include boarders, sub-tenants and joint occupiers.
Housing Benefit and Council Tax Support are normally reduced by a specified amount for each non-dependant (because it is assumed that they can contribute to household expenses). The amount of the deduction from your benefit is based on the non-dependant's income. If you cannot give us the non-dependant's income, the maximum deduction will be applied. Money received from boarders and sub-tenants would be included in the assessment of your income.