We have developed an attributable cost model for a city-based telecare scheme involving 11,618 community alarm users. The equipment was assumed to cost 500-1000 per installation, compared with 175 for the current system. Because of the significant additional capital cost of the proposed system, it would be necessary to borrow to finance it. For example, if the home equipment cost 500 per unit, an additional 2.2 million would be required. Nonetheless, it would be possible to achieve a return on the investment after 10 years. The principal savings would arise from reduced hospital bed costs and reduced residential care. The model suggests that the financial benefits of the proposed system would occur in the ratio of 4% to the local authority housing department, 43% to the National Health Service and 53% to the residential care provider.