The basic rule
Lifeline is generally limited to one benefit per household. A household is a group of people who live together and share income and expenses. It is not simply everyone at one street address.
Separate households at one address
If you live with another Lifeline user but do not share money for household expenses, USAC may ask you to complete a Household Worksheet. Answer honestly in the official application.
Check the official source for current rules and figures.
USAC: Lifeline FAQ ↗