There was a discussion on this topic but has been closed.
(Where to set up company Tax-ID?)
I don’t know since what ERPNext version, but there is redundancy for the Tax ID entry.
There is the Registration Details text box. And yet there is a Tax ID entry field also.
Unless there is a specific use for the TaxID field, I think it should be merged with the Registration Details.
And to go further, make the Registration Details a child table. This way it can be retrieved for other purposes.