The importance of the services-based market, 62.9% of the World gross domestic product (GDP), triggered an increase in the use of software offered on-line as services (SaaS). The use of such software usually implies the flow of personal data on-line between several parties. This can make users reluctant to their use. In this work, we consider this issue at the design-time of the software and we propose some foundations for an accountable software design. Accountability for a software is a property describing, among other aspects, its liability to end-users for the usage of the data it has been entrusted. We propose to enrich software's component design by accountability obligations using an abstract accountability language (AAL). We also define conditions for the well-formedness of an accountable component design and show how they can be checked using a model-checking tool.