The issues, to me at least, are these:
1) are the couple are spending a significant amount of their time together? (at this stage, ignore which address).
If no, it seems there are two separate households and, in turn, 2 HB/CTB claims would be appropriate.
If yes, next issue….
2) If the couples’ together time applies to BOTH addresses, two issues need to be considered:
– how much time together?
– if sufficient time is spent together, which is the MAIN address?
If either (or both) continue to be vague about living arrangements, write to both of them asking straighforward questions about where they live and when. If they don’t respond, or fail to provide the info requested, you can follow the DAR route (suspend / terminate).
You could also request an interview (under cautioin?), but this can’t be forced.
NB: just wondered if the following case law assists (on bailii)?
MULLANEY (& CLAYTON) v Watford BC & Anor [1997] EWHC Admin 28
Regards