So while shopping in a store tonight I witnessed a store clerk allow a customer to use their ID to buy cigarettes. The store clerk ask me if I could allow the customer to use my ID. I clearly and quickly told her that, I could not do that. The lady claimed to be of age. To me as a person with an MBA, would without reservations would say it is ethically wrong. I can’t find anything that states it is wrong, even though I know it is legally wrong.
The law is a blanket prohibition on selling tobacco to persons under 18 years of age. There is no requirement on the retailer to verify the age of the customer: they are simply liable if the customer happens to be under 18.
Government advice is that proof of age should be requested of any customer who appears to the retailer to be under 25 years of age and only certain types of ID are acceptable. It is a defense to the otherwise strict liability offence if ID was observed that could reasonably be accepted by the retailer (i.e. a good forgery would meet the criteria) AND the customer was at least 14 years old. there is no requirement to record that this happened - presumably the testimony of the sales clerk would suffice if credible.
So, for the particular circumstances: if the person was 18+ there is no illegality, if the person is less than 18 there is no defense because your ID is not a valid ID for the under-18 purchaser.