Do all executors named in the Will have to act in the administration of an estate?

Whether a grant needs to be obtained usually depends on the assets in estate. For example you have to have a grant to be able to sell or transfer property.
Banks and building solicitors have the discretion to pay out the contents of accounts without seeing a grant if the total value of the estate is below a certain threshold. This is usually between £10,000 to £25,000 depending on the bank. Otherwise a grant will be required.

The grant of probate is a certificate provided by the Probate Registry of the Court which confirms that executors named on the grant have the authority to deal with the administration of the deceased’s estate.

When someone dies without leaving a valid Will a grant of letters of administration will need to be obtained to enable the beneficiaries of the estate to administer it. Under the Intestacy Rules the people entitled to take out the grant are the beneficiaries of the intestate estate. They are known as the administrators opposed to the executors. They will be unable to administer the estate without a grant of letters of administration.

If you own any assets then yes.  If you die without a valid Will your assets will pass in accordance with the Intestacy Rules.  In many cases these rules will not reflect you wishes and could result in claims being brought against your estate from disappointed beneficiaries leading to unnecessary costs eroding the value of your estate.

Yes.  There are five grounds upon which you can challenge the validity of a Will:-

a)    The deceased did not have the necessary mental capacity at thetime the Will was made;

b)    The deceased did not know or approve the contents of the Will;

c)    The deceased was coerced or unduly influenced into making the Will;

d)    The Will is a forgery or it was fraudulently created;

e)    Lack of proper formalities – you can contest the validity of a Will if it was not correctly witnessed or otherwise was not properly executed.

Please note there are other claims you can bring against an Estate in addition to disputing the validity of a Will. These include seeking to enforce a promise made to you by the deceased, a claim for reasonable financial provision where the deceased has not made reasonable provision for you and/or asserting an interest in property or assets owned by the deceased to which you have contributed.