Family Lore Clinic: What do I do after I dispense with service of the divorce petition?
If you wish to take divorce proceedings then you will normally have to serve the divorce petition upon your spouse. However, if you do not know their whereabouts (having made reasonable efforts to find them) then you can request the court to dispense with service.
The procedure on a request to dispense with service is to complete a statement in support of the request and file it with the court, along with the requisite fee. You can find a statement here, together with notes for guidance.
If the court grants the request, then you can simply proceed with the divorce as if it were undefended, i.e. apply for the decree nisi. For information upon how to do that, see this leaflet, prepared by the Courts Service.
Obviously, if you do not know the whereabouts of your spouse, then you would not be able to divorce them on the basis of two years' separation, as that would require their consent.
(If you require more details or specific advice, you should consult a specialist family lawyer.)