What does it mean to be self-sufficient?
You are self-sufficient if you are not employed or self-employed and you rely on your own savings or others’ income to live in the UK.
For example, an EU student whose parents send them monthly payments for their living costs, but who does not work, is a student who is self-sufficient. An EU citizen who is relying on a partner’s income and staying at home with children is self-sufficient.
Self-sufficient people need CSI to exercise treaty rights.
Note: this question, like other FAQs on Comprehensive Sickness Insurance (CSI), relates to applications for British citizenship, when considering whether periods of past residence were lawful. the3million’s Young Europeans have published a very useful document on key Citizenship facts which you can find here: http://www.t3m.org.uk/t3m_YE_KeyCitizenshipFacts.
CSI is not required to apply for pre-settled or settled status under the EU Settlement Scheme. Also, once pre-settled or settled status has been granted, you are lawfully resident, and you do not need CSI.