Do the two parents have to reside at the same address to be classed as a family? I have been in a 20 year relationship with the same person. We have a child together, but we have chosen not to live together. Can we purchase travel insurence as a family?

The other thead at the bottom seems to point to the requirement that you live at the same address, although you can legally define anyone with the same blood ties as your family.

family n. 1) husband, wife and children. 2) all blood relations. 3) all who live in the same household including servants and relatives, with some person or persons directing this economic and social unit.

Sources=Sources | 4096;law()

However it seems that most, if not all travel insurance insist you live at the same address, in order to qualify.

http://www.moneysupermarket.com/community/forums/t/travel-ins-23310.aspx