commonlaw partner

[evertonsue]

What is a commonlaw partner?

[Clanad]

While not being sure of the terms meaning in the U.K., here in the U.S., an unmarried couple who live together for a given period of time, usually seven years, but dependent on the individual State's laws, are then considered to be legally married under "common law".  The wife and any children accumulate rights not vested in an unmarried partner of less than the seven years...

[Karen2005]

There is no such thing as a commonlaw partner in English law:

It is a widely held belief that there is such a thing as a common law wife or husband. In fact, since the Marriage Act of 1763, there has been no such thing in England and Wales. Whether you live with your "partner", "cohabitee", "live-in-lover", "domestic associate" or "current companion" in the eyes of the law there is no special relationship and you are not equivalent to a husband or wife.

See http://www.divorce.co.uk/hottopics/articles/cohabitants.htm

for more information.