This has previously only been available to same sex couples.
Following a legal challenge the Government changed the legislation to extend it to heterosexual couples as well.
It is a formal procedure and notice has to be given (similar to Banns on marriage)
Once entered into it affords couples similar rights and protection as married couples.
It does not however convey Parental Responsibility so if a fathers name is not on the Birth certificate an application for Parental Responsibility would have to be made(legal aid would not be available for this in this context as there would be no dispute and no evidence of domestic abuse as the couple would be in a relationship)
If the relationship breaks down there is a formal procedure to end the Partnership and the Court have the power to make financial orders.
Therefore if you are not married but want some of the financial security that married couples have but co habiting couples do not then you should consider a Civil Partnership.
Remember “Common Law Spouse” does not exist .If you are not married or in a Civil Partnership as set out above you may find that if the relationship breaks down you have no financial protection.