GETTING bills in the post and paying for stuff in cash means you are past it, according to millennials.
Having a Facebook account and smoking are further giveaways of advancing age, those aged 25 to 40 suggest.
Using a mobile to have a conversation with someone and calling a tune “banging” also meant your young days are behind you.
Going to church, writing lists with a pen and paper and ringing for a taxi were other “oldie” clues.
Joint biggest no-no was having a handkerchief up your sleeve, which horrified 28 per cent of millennials, along with using cash.
Getting paper bills delivered to your home was next with 25 per cent, followed by having posh cutlery for special occasions on 24 per cent.
Some 2,000 millennials — those born between 1981 and 1996 — were polled by retailer Love Energy Savings, which encourages firms to switch suppliers online.
Boss Phil Foster said: “Today’s millennials are left scratching their heads by behaviour that was once entirely par for the course — like watching conventional, broadcast TV and actually using your mobile phone to talk to people.”