Background: The daily management of long-term conditions falls primarily on individuals and their informal carers, but the household context and its impact on health and social care activity among people with multimorbidity is understudied.Methods: Linked data from health providers and local government in Barking and Dagenham provided a retrospective cohort of people aged 50+ in two-person households between April 2016 and March 2018. Two-part regression models were applied to estimate annualised use and cost of hospital, primary, community, mental health and social care by multimorbidity status of individuals and co-residents, adjusted for age, gender and deprivation. Applicability at the national level was tested using the Clinical Practice Research Datalink.Results: Over 45% of multimorbid people in two-person households were co-resident with another multimorbid person. They were 1.14 (95% CI 1.00, 1.30) times as likely to have any community care activity and 1.24 (95% CI 0.99,1.54) times as likely to have any mental health care activity compared to those co-resident with a healthy person. They had more primary care visits (8.5 (95% CI 8.2,8.8) vs 7.9 (95% CI 7.7,8.2)) and higher primary care costs. Outpatient care and elective admissions did not differ between these groups. Findings in the national data were similar.Conclusions: Care utilisation for people with multimorbidity varies by household context. There may be potential for connecting health and other community service input across household members.