TCTM09347 | Decision Making, Joint or Single claims, Considerations when deciding if two people should be treated as a couple: Public acknowledgement
From HM Revenue & Customs · Tax Credits Technical Manual
If two people who live together have represented themselves as a couple to others this may be an indication that they are living together as husband and wife (LTAHAW) or as civil partners (LTACP), although this is not conclusive. Two people who are a couple may by choice not want to be publicly acknowledged as a couple for personal reasons.
Relevant factors may be:
whether both members use the same surname
whether family, friends, neighbours, social workers, employers, schools, childcare providers (or any other people) regard them as a couple
if they take part in social activities together
if they are joint members of clubs/leisure centres/societies
whether they plan and organise their lives jointly
if they are represented as a couple:
on the electoral register
in claiming benefits
in obtaining accommodation
Note: this indicator should not be used in isolation as all factors should be considered as outlined in TCTM09341.