There are two options, only one provides you with a formal ‘legal status’, that is judicial separation. This is in effect the same process as a divorce in that it will be considered by a Judge and financial claims can be made against the other party. Generally Judicial Separation is used by those who for religious or cultural reasons are not wishing to be divorced.
The alternative is to enter into a Separation Agreement or Deed of Separation, this does not change your legal status, it is used most often by couples who do not wish to divorce immediately but wish to formalise their separation.
Usually the Separation Deed will specify a timescale within which one party will issue divorce proceedings and that the other party will consent. The separation deed can set out the financial arrangements, such as whether to sell a property, how to divide the proceeds of sale and any other assets and whether maintenance is going to be payable.
Couples need to be aware however that, even if you have such an agreement and set it out in a deed, when a divorce is issued the court can still make orders about financial issues.
This is the case even of you have already reached an agreement, if for example the court does not agree that your agreement is appropriate, or, the other party changes their mind about what you agreed when you separated, the court may take into account an agreement set out in a separation deed but the court is not bound by it so you do need to think carefully about whether it is better to divorce as soon as possible.
It is invariably better for both parties if you divorce at the time you separate because it means an agreement can be made legally binding on both of you in a consent order, there is no ‘comeback’ at a later date and so it provides certainty for both parties.