The Supreme Court ruled yesterday, in the case of Gow v Grant, that cohabiting couples should be able to make financial claims on the basis of fairness.
More than 150,000 couples cohabit in Scotland but lawyers fear few of them are aware of their legal rights.
Gillian Crandles, cohabitation expert at Turcan Connell, said: "Although all family law cases are fact-specific to some extent, the judgment may have far reaching implications for all cohabiting couples should their relationship come to an end.
"The judgment also states reference could be made to the prevailing legislation regarding financial provision on divorce, which perhaps goes further than many might have expected.
"Through this judgment, it is becoming clearer that the consequences of ending a relationship may go way beyond emotional turmoil.
"Many of the growing number of cohabiting couples won't be aware of this, which is why a public information campaign now needs to be put in place to educate people.
"Couples who don't want to fall into this type of legal battle in the event of separation ought to put in place a pre-cohabitation agreement, opting out of this regime given its potentially far-reaching consequences."
Scott Cochrane, head of family law at Brodies, said: "Love is blind. Many couples think that because they are living together they have the rights of common law husband and wife but that is not the case.
"People may also not know that there is no minimum period to qualify as cohabiting.
"This has given people the protection of cohabitants' rights in Scotland. At least, unlike in England and Wales, we have a remedy for cohabiting couples.
"The Supreme Court has said we must take a broad brush approach to assess where the couple were at the beginning and where they were at the end.
"It is about simplicity and fairness. Unlike divorce, there is no incentive to co-operate but what this does mean is that there is a remedy for cohabiting couples."
Legislation in 2006 gave specific provision to those living together out of wedlock in Scotland.
Ms Jessamine Watson Gow was subsequently granted £39,500 for financial disadvantage in 2009 after her relationship with Angus Grant ended.
After they moved in together in 2003 Mr Grant encouraged her to sell her house. She sold it for £50,000. By the time they reached court the value of the house had increased to £88,000.
The sheriff considered the difference between the sale price of the house and its current value represented an economic disadvantage to Ms Gow and that difference should be taken into account in assessing compensation.
However, a Court of Session appeal by Mr Grant overturned that decision and led to a ruling restricting cohabitants' ability to make financial claims if they split up or one person died – including the stipulation there had to be evidence the defendant intended to benefit.
Yesterday the Supreme Court said the legislation should be interpreted more broadly.
Comments from the Supreme Court suggest a remedy is now required south of the Border.
A summary of the judgment stated: "The main lesson from this case, as also from the research carried out in Scotland and England to date, is a remedy such as this is both practicable and fair, focusing on where parties were at the beginning of the relationship and where they are at the end.
"It does not impose upon unmarried couples the responsibilities of marriage but redresses the gains and losses flowing from their relationship."