The process of applying for probate is the same for everyone in England, Wales, and Northern Ireland. However, in Scotland this is known as confirmation.
Regardless of who applies (executor or Next of Kin) both must prepare the deceased's financial information for the court.
Once this is collected the executor must submit this alongside the will so the court can determine whether the will is accurate. The Next of Kin will just submit this information so it can be reviewed by the court and so they can distribute it themselves.Once this has been approved by the court the person in charge of the estate (executor or Next of Kin) will be able to distribute the assets. The executor will do this based on the will whilst the Next of Kin will do this based on inheritance law.
Most estates do not need to apply for probate, if the estate is made up of jointly owned property and money these will pass to the surviving owners and the spouse/civil partner
To learn more: Applying for Probate