Pension Credit Severe Disability Premium

Can anyone advise please?
I have a client who has recently been awarded AA. He is currently receiving Pension Credit as a single person because, although he lives with his wife who is his carer, she is a Zimbabwean national and at present has no recourse to public funds. They have no income other than his SP and PCr. They get full H/CTB.
My query is whether he will be entitled to the SDP as a person technically living alone or whether his wife counts as an adult in the household even though he cannot claim for her?

I don’t think so. The test isn’t “do you share a household for benefit purposes”, it’s “does someone normally reside with you”.

[In the very unlikely event that the CTB claim becomes an issue for recourse to public funds, i.e. by her presence they are now receving 100% CTB instead of 75% CTB, I suppose they will have at least have an argument that the loss of SDP will more than have offset that “drain” on the public purpose.]

when partner receives Ni No can they only apply for CA or couple rate from date of Ni No being received?