This policy brief by Dr Rita Griffiths and Dr Marsha Wood summarises the findings of research which tracked month-to-month changes in earnings and household income, in real time, between 2022 and 2023, among 61 Universal Credit (UC) claimants in 42 working households with one or two earners in paid work or self-employment. A key focus was the system of monthly assessment, in particular the monthly means test, in which the UC payment is automatically adjusted upwards or downwards based on reported changes in a household’s income in the previous month.