The Bona Vacantia Division (BVD) would prefer that you do not send in original documents. Instead please send copies of the originals certified as true copies by:

• The Post Office checking service or a practicing UK Solicitor (in the UK)
• Notary Public or Apostille (outside the UK)

More details can be found at:
Estates – Making a claim to a deceased persons estate
Companies – Dissolved Company Guidelines and Proof of Identity Checklist

In addition the making a claim to a deceased persons estate guidance has also been updated