This is why it is especially important for any unmarried couples considering moving in together to sign a co-habitation agreement, particularly if you are a high net worth individual with large amounts of assets. Co-habitation agreements can also be prepared after you have moved in with your partner. Co-habitation agreements are important in the event of a relationship breakdown as they enable you to make sure that you and your assets are fully protected. If your partner owns the property that you are living in and the relationship breaks down then you won’t be entitled to any share of that property, except in some unusual circumstances. However, if you buy a property together as joint tenants then you will usually own half of the property each, despite what you each contributed financially towards it.
If you are living with your partner you may acquire some rights under general property law but this area of law was not built specifically for cohabiting couples and is unlikely to adequately cover your needs.
If you have children with your partner then you can apply for maintenance for them even if you are not married. Maintenance is not possible if you don’t have any children.