Aim: To examine the association between informal carer availability and transitions to permanent residential aged care (PRAC) among individuals initiating long-term home care. Methods: We conducted a population-based retrospective cohort study using the Registry of Senior Australians National Historical Cohort. Non-indigenous individuals 65-105 years old who initiated long-term home care (i.e., Home Care Package) in four Australian states between 01/01/2012 - 31/12/2019 were included. Informal carer availability was ascertained from individuals’ most recent aged care eligibility assessments. Time to transition to PRAC within five years, with death as a competing event, was the outcome of interest. A multivariable cause‑specific Cox model adjusting for confounders was used. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CI) were reported. Results: Overall, 198471 long-term home care recipients with known carer status (81.5% reported an informal carer, median age 83 years, 61.9% women, 19.3% had dementia) were included. Within 5 years of initiating long-term home care, the cumulative incidence of transitioning into PRAC was higher among long-term home care recipients with an informal carer (53.4%, 95%CI: 53.1-53.7) compared to those without an informal carer (43.1%, 95%CI: 42.4-43.9). After adjustment, those with an informal carer had a 34% (aHR 1.34, 95%CI 1.31-1.37) higher risk of transitioning to PRAC. Conclusion /implications: Our findings suggest that long-term home care recipients with an informal carer had higher risks of transitions to PRAC. While greater insight into types of informal care support is required, these findings highlight that interventions to support informal carers may influence individuals’ transitions to PRAC.