Take legal advice before buying a property jointly with another person. In a recent case the court held that cohabitants owning a home in joint name were entitled to 50% each even though one has not lived there nor contributed to it since 1993.
There was no intention to share differently from 50%. Obviously it is fairly simple to have an agreement setting out different percentages but if people fail to do this then the 50% shareholdings each still stand.
This case Kernott v Jones  EWCA Civ 578 confirmed the existing law and said that there was “a total lack of evidence about the parties’ intentions” and the Court of Appeal overturned the courts below which had given the remaining cohabitant 90%. They had bought the house together in 1985 and he moved out in 1993. The other cohabitant then paid the rest of the mortgage and funded their two children.
If you propose to cohabit rather than marry then do be aware there are significant legal differences and take legal advice. It is not difficult to draw up a document ensuring the percentage shares reflect the parties’ intentions and the percentage shareholdings can even be registered at the Land Registry.