The people administering the estate need to obtain a Grant of Representation before they can begin. This is a legal document, from the Probate Registry, and authorizes a person or persons to collect the money and assets, pay outstanding bills and distribute the estate. Banks, insurance companies, and other organisations will need to see this document before releasing any assets.
If the estate is held jointly and everything passes to the surviving owner then you will not be required to apply for probate. Also, if the estate is very small some organisations may release the money without the need for a Grant of Representation.
Visit DirectGov website for more information and the appropriate forms to be completed.