Answer
A couple that is cohabiting is one that is living together without being in a civil partnership or a marriage. On the other hand, a civil partnership is a legal arrangement whereby a couple (same-sex or opposite-sex) who aren’t related enter into a registered legal union.
Unlike cohabitation, a civil partnership gives the partners more legal rights and responsibilities towards each other during and when the relationship ends. However, cohabiting partners can draw up an agreement, known as a cohabitation contract, outlining their legal rights such as property ownership, parental responsibility, joint-ownership of possessions, etc.
In summary, here are some differences between cohabiting and civil partnership:
Legal recognition: A civil partnership is legally recognised, whilst cohabiting is not.
Ending the relationship: Cohabiting partners can end the relationship informally without court involvement while ending a civil partnership requires applying to the court for an annulment/dissolution.
Financial support: In a cohabiting arrangement, partners do not have a legal responsibility to support each other financially once the relationship ends, unlike in a civil partnership where the law requires them to support each other.
Housing (rented accommodation and owner-occupied): The partner who owns the home or is the named tenant can request the other to leave in a cohabiting relationship, while civil partnership grants a partner the right to stay no matter who the named tenant or homeowner is.