Hi BJ
You need to get specific personalised advice regarding this as some mixed aged couples are protected and don't have to claim UC when one member of the couple reaches pension age.
Also the DWP with Managed Migration are telling the partner in an ESA claim wrongly that they have lost their Support Group or WRAG status and that they must supply Fit Notes despite have had a WCA in the past when they had a single person's ESA claim.
You could try phoning the Citizens Advice Help to Claim service for advice.
David
Nothing on this board constitutes legal advice - always consult a professional about specific problems