Wet signatures from client

Today a question cropped up – should accountant always take wet signatures from clients as their approval?

HMRC is of the opinion that it is not compulsory.

Client can give approval by electronic or non-electronic means.

Source Link: http://webarchive.nationalarchives.gov.uk/20140206222144/http://www.hmrc.gov.uk/ebu/2012-copyspec.pdf