Brilliant thread - such a laugh. I shall adopt the telephone advice given by Bags. I loathe giving out my mobile number, and the land line usually only rings these days when it's a pest of some kind or other.
My inner anarchist was let lose when my youngest daughter had issues with the DVLA but work hours meant she couldn't phone them. I became her. My sister once masqueraded as her son who was living abroad and needed to speak to the DVLA/Insurance company etc. When she phoned and explained he was under 21 and abroad, and she was his representative on earth, i.e. his mum, no-one would talk to her. In desperation, she phoned and when asked are you ** she said yes, I am, and no=one challenged this 50 plus woman as not being a young man. All 3 of mum's daughters began to masquerade as her when her deafness and lack of sight made it hard for her to speak to the bank etc.