Under the supplementary welfare allowance (SWA) scheme, a weekly supplement may be paid in respect of rent or mortgage interest to people in receipt of social welfare or health board payments. Entitlement to a supplement is determined by the health boards. Supplements are calculated to ensure that the person, after payment of a rent which the health board considers appropriate, having regard to the nature, character and location of the residence, has an income equal to the rate of SWA appropriate to the family circumstances, less £6. This £6 represents the minimum contribution which clients are required to pay from their own resources towards their accommodation costs.