Whilst the article below primarily deals with the identification of beneficiaries when dealing with the distribution of an estate, the principles apply equally to identification of executors when a firm is asked to hand over an original Will.
Once the death has been established you need to ensure the person before you is the actual executor. Similarly are they the only executor? Often one person named will assume they can obtain the original without involving others. Not so. All named executors entitled to take the Grant of Probate should authorise the release of the Will. Their ID should be obtained and verified if necessary. This is particularly important if there is any potential for a dispute over the Will or the estate as releasing the Will means one individual could try to extract a Grant on their own, bypassing the others. If you are being pushed for release on the basis of 'urgency' then this is always a red flag and there is no reason you should not ask what that urgency is - albeit it will not remove the need for due diligence in identification.
It can often be time consuming to obtain necessary ID but don't be afraid to ask for direct contact details for individuals and ensure you speak to people rather than rely on messages being passed on. Taking time to ensure all executors truly agree to the original Will being sent out (and on this a traceable method of post is always advisable if it is not being collected in person) could save time dealing with complaints afterwards.
Addressing ID checking when it comes to, not only Executors but also Beneficiaries, is a vital part of the Know Your Client, or KYC, process