Over four in ten (42%) of parents have taken out life insurance, and 20% have made a will, research from Aviva has found.
Savings were much more common, 52% having opened a savings account in their children's names.
A smaller proportion, 37% of parents had opened a junior ISA or Child Trust Fund and 8% having started saving for a house or university costs.
The research found that by a child's fifth birthday on average parents have spent around £35,000 on their children, with London spending 53% more than the national average.
The region with least spent per child was Wales spending £4,900 on each child per year compared to London's £10,731.
Aviva conducted the research among over 2000 UK parents for the relaunch of its free parent life cover which offers £15,000 of life insurance to parents up to the child's fourth birthday.
Louise Colley, protection director for Aviva said: "As every parent knows having children can be an expensive business, but it's incredible to see how this stacks up over the years!
"This is why it's so important for parents to consider how they might cover the cost of raising a child if they were to unexpectedly lose an income through illness or even worse, bereavement.
"It's reassuring to see that four out of 10 parents with under fives have taken out life insurance, but we'd encourage the remaining six in 10 to consider the ‘what ifs' and take steps to protect their loved ones' futures.
"Aviva is offering a year of free life cover worth £15,000 per child, per parent for parents who register before their child's fourth birthday, so this is a fantastic simple way to get some peace of mind, knowing that some cover is in place."
Sue Clark appointed as senior underwriter
From 20 April
At the end of National Heart Month
Ruth Gilbert investigates another potential threat to life policies
Created for clients who might have rejected life insurance