Earlier quoted context omitted.
What do you mean "required"? Like, they wouldn't accept a clean, non-scanned copy? That's absurd.
Some types of documents/deeds do require "wet ink" signatures by law - https://www.lawsociety.org.uk/support-services/advice/articl...
> If you’re a solicitor responsible for registration, you need the other parties' solicitors, on closing, to send you the wet-ink signed parts of the documents. You’ll only proceed when you have the wet-ink signed documents, not when you have seen electronic images of them.