BACKGROUND: Telephone advice lines have been recommended internationally to support around-the-clock care for people living at home with advanced illness. While they undoubtedly support care, there is little evidence about what elements are needed for success. A national picture is needed to understand, improve and standardise service delivery/care. AIM: To explore telephone advice lines for people living at home with advanced illness across the four UK nations, and to construct a practical framework to improve services. DESIGN: A cross-national evaluation of telephone advice lines using structured qualitative interviews. A patient and public involvement workshop was conducted to refine the framework. SETTING/PARTICIPANTS: Professionals with responsibilities for how palliative care services are delivered and/or funded at a local or regional level, were purposively sampled. RESULTS: Seventy-one interviews were conducted, covering 60 geographical areas. Five themes were identified. Availability: Ten advice line models were described. Variation led to confusion about who to call and when. Accessibility, awareness and promotion: It was assumed that patients/carers know who to call out-of-hours, but often they did not. Practicalities: Call handlers skills/expertise varied, which influenced how calls were managed. Possible responses ranged from signposting to organising home visits. Integration/continuity of care: Integration between care providers was limited by electronic medical records access/information sharing. Service structure/commissioning: Sustained funding was often an issue for charitably funded organisations. CONCLUSIONS: Our novel evidence-based practical framework could be transformative for service design/delivery, as it presents key considerations relating to the various elements of advice lines that may impact on the patient/carer experience.