WhatsApp is raising its minimum age from 13 to 16 across Europe.
It will ask people to confirm how old they are when new terms are rolled out in the coming weeks.
It is unclear how this will be checked, though.
Social media expert, Toby Beresford, says not all parents will be pleased.
Mr Beresford said: "If you're a family and you've been used to using WhatsApp asa way of keeping the family conversation going while everybody's abroad then you might have to look for a different supplier."
He also said they may ask for ID to verify a users age when they sign up.
Mr Beresford said: "They make you take a photograph of your passport or a photo of your driver's licence and that gets electronically viewed and scanned.
"Those are the sorts of measures you would expect a company like WhatsApp would take eventually, but there's plenty of room for people to make false declarations."
- Digital Desk