The TV and outdoor ads, which break this week and run until October 31, encourage people aged 35-plus to use their mobile spontaneously.
Vodafone's head of advertising, Guy Phillipson, said: "Once you get to the over-35s, the more fluid way people use their phones tends to drop off.
"They tend not to use their dead time waiting in traffic to make calls, and are less likely to have personalised voicemails or send text messages."
The TV ad, comprising a 60-second spot and 20-second cuts, features a man on his way to buy a paper, to a soundtrack of The Faces' When I was Younger. The things he sees on his way remind him of friends and relatives he should call to keep in touch, with the endline 'Now is good'.
It has been created by Wieden & Kennedy Amsterdam and adapted by J Walter Thompson for the UK.