ESA & SDP

Hello, i have a client who is on DLA HR mob & care, she lives with her 2 children aged 12 and 18, the 18 year old attends college full time and client receives CB for him; she has recently seperated from her partner who was in receipt of IS & Carer premium.
Due to change of circs, client claimed IR ESA and was sent SDP forms.
We sent SDP forms off and client heard nothing further so we chased it up last week to be told there there was note on system that client not entitled to SDP as she has 18 year old son living with her. I queried this as my understanding is that as her 18 year old is in full time education and she receives CB for him his presence in house should be ignored; was told situation would be looked at again and client would receive call back.
Client did receive call back to be told that no, she is definitely not entitled to SDP.
I have checked (and checked again!) in both CPAG and Disability Rights Handbook and unless i am misunderstanding both books i am sure her 18 year old should not be classed as non dependant and therefore his presence in house should be ignored? Any thoughts on this matter greatly appreciated!

It sounds like the problem is with her ex. If he was getting the carers premium then he might have been receiving Carers Allowance.  Is he still getting Carers Allowance?  If so then no SDP.  The rule doesn’t apply if he only has underlying entitlement.

Hi thanks for all your help. Clients ex has stopped getting Carers Allowance, and i did reiterate when i spoke to ESA dept on phone that client got CB for son, info that i was advised would be emailed to correct team who would then call back client.
Another letter they shall be receiving then pointing out that they have made an error (shock, horror & surprise!)
Thanks again and have a good afternoon!