Objective: To explore care workers’ experiences with a flexible planning of home-based postpartum care as an innovative instrument to facilitate more client-centred care. Design: A mixed-methods design with a primarily qualitative approach followed by a quantitative follow-up, according to the Priority-Sequence model. Setting: This study is part of a larger research project researching the health effects of a flexible planning in postpartum care. The new planning enables clients and care workers to spread and/or pause the care over 14 days postpartum instead of the standard planning of eight to ten consecutive days. Participants: Maternity home care workers who provide care according the flexible planning. Eight care workers were interviewed, another eight care workers participated in the focus group discussion, and 59 care workers filled in the survey. Findings: Two main unintended consequences of the flexible planning were found: 1. care workers experienced an undesirable ‘shift in their tasks’ along the course of the postpartum period and 2. were heavily worried about ‘making enough contracted hours’. Consequently, care workers unwillingly performed much more domiciliary activities compared to the standard planning, especially during the final days of care. Key conclusions: The predominant nursing tasks and responsibilities of care workers appeared insufficient to respond to clients’ altering needs. In addition, shorter working days and on-call duties caused an undesired excessive high-level of flexibility among care workers. Consequently, care was paradoxically determined by organisational structures rather than clients’ individual needs. Implications for practice: Our study elucidated that co-creation together with health professionals is a prerequisite for successfully implementing innovations as their way of working and personal lives are profoundly affected.