MoneyHelper said children can start building money skills from age 3, using the summer holidays as a practical window for parents to teach budgeting, spending and saving.
James Kelly of the Money and Pensions Service tied the advice to rising holiday costs, with days out, kids' clubs and teenagers borrowing money putting extra pressure on family budgets.
Age-specific tips range from playing shop at 3 to 4 and helping with food shopping at 5 to 6, to setting activity budgets over the 6-week break for children aged 7 to 8.
For ages 9 to 11, the guidance shifts to banking and top-up cards, while teenagers with summer jobs are encouraged to learn from payslips, budgeting and earning money through chores.
MoneyHelper said its free Talk Learn Do resources and teen guidance are meant to turn small summer money conversations into long-term financial confidence.