Resident Certificate for EEA national (Italian) who is unmarried partner of British citizen

Is it imperative for an Italian national, arrived in UK last year, to live with unmarried partner, a British National who has right to reside as never left UK,  to have a “resident certificate” before they can claim and get paid Benefits such as ESA, JSA,  or CTC as a couple?

Do they need to fill in EEA ( EFM ) application   or not?

If the British citizen has never left the UK, his Italian partner does not gain any EEA residence rights through him at all: if s/he is intending to claim benefits in his/her own name that have a right-to-reside requirement, s/he will have to establish his/her own right of residence through economic activity.

However, assuming they are going to live as a couple in the eyes of the benefits authorities, for most benefits the British citizen can be the claimant and the EEA partner’s right to reside does not affect anything.  The only exceptions are UC and CTC, which would be restricted to the rate for a single person, and joint-claim JSA which I think would be paid at couple rate but with some hassle in the claim process.

Now I suppose you are going to tell me the British citizen is a full time student ...

Thank you- will test it.