Background: This study explores communication partners' perceptions of their roles and responsibilities in the design, planning and use of augmentative and alternative communication (AAC) with individuals with severe/profound intellectual disability. Methods: A qualitative descriptive approach was used. Purposive sampling, data collection and qualitative content analysis were undertaken simultaneously. Data were collected from nine participants, four parents and five professionals over 4 months through audio or video-recorded, semi-structured, open-ended interviews. Findings: An overarching theme 'Maximising Communication through AAC' emerged, capturing participants' unanimous agreement that their shared goal was to optimise individuals' communication through AAC. This was influenced by three themes: 'Developing a Communicative Environment', 'The Act of Communicating; Attempting to Realise the Individuals' Ability' and 'Living with Uncertainty'. Conclusions: These findings contribute to enhancing understanding of AAC use with individuals with severe/profound intellectual disability and their communication partners.