The non-profit sector worldwide has undergone significant change brought about by public sector reforms with the introduction of New Public Management practices. The associated outsourcing of social services has shifted accountability to non-profit organisations (NPOs) and they are being forced to develop and expand their ICT capacity to meet various government reporting obligations. However, ICT-induced organisational change within NPOs has proved problematic, often leading to failure. This thesis focuses on medium and large scale NPOs delivering social services on behalf of government. Not all change management and other business practices from the private and public sectors are suitable for use in NPOs (despite these being imposed upon them) due to differences in the authority structures, mission, culture and motivation factors of non-profit workers. It has been demonstrated that the motivation of workers (a key differentiator between the sectors) to undertake and persist with organisational change and accept technology is crucial for success; and it is particularly important for NPOs to maintain worker motivation when undergoing change. The empirical investigation component of this research project was informed by means of a critical analysis and synthesis of the literature in a range of reference disciplines, which provided a strong theoretic framework for the remainder of the work. Key initial theoretical foundations of the project include: the dissection of motivation informed by Self Determination Theory; Frey's Motivation Crowding Theory and the substantial literature concerning technology acceptance, rooted in Davies' TAM, which underpins much thought within the Information Systems community about employee acceptance of technology. Using a multi-cycle Action Research study undertaken within an exemplar NPO, the project focused on the creation, testing and refinement of an autonomously-supportive organisational change implementation strategy; and the development of an associated Motivational Technology Acceptance Model (MTAM) suitable for NPOs. The autonomously supportive interventions promoted internalisation of the change process, leading to the use of a more integrated or identified type of self-regulation as well as evidence of a more autonomous type of motivation to accept the change. This, in turn, reduced the crowding-out effect caused during the implementation of the change process. In addition to offering a path reducing long term failure rates in NPOs' organisational change projects, this thesis provides the IS community more broadly a deeper and more thoughtful treatment of motivation, offering practical guidance to NPO managers implementing an ICT-induced organisational change.