Hello Ellie - I have not had any response so have set out a response which hopefully will answer your question.
An application to register the beneficiary of the share of the deceased proprietor using a form AS1 is not correct. The form AS1 clearly indicates that it is for Assent of whole of registered title.
Where the property is registered in the names of two people, one of whom has died, the personal representative of the deceased proprietor cannot as assent a share in the legal estate. The legal estate automatically vests in the surviving proprietor. Only the deceased proprietor’s beneficial interest passes on under the terms of their will or intestacy.
Please refer to the guidance on our website on How to update property records when someone has died. You may also find the information in our Practice Guide 6 of use.
I hope this helps.