What money mistakes might my child make once they leave home?

The most common mistake is thinking day by day instead of month by month. Without an overall view, each single purchase seems reasonable, until their sum exceeds what's left in the account.

This habit is easy to correct: note down all expected income and expenses once a month, before spending day to day without a plan.

Insurance, equipment renewal, back-to-school costs: these yearly expenses are often missing from a monthly budget, even though they always come due eventually.

A young adult who discovers an annual bill without planning for it often has to borrow or delay a payment, which carries an avoidable cost.

• List once the expenses that come back every year.
• Divide their total by twelve to fold them into the monthly budget.
• Set that amount aside before it's needed.

A subscription, an installment plan, or an overdraft facility is often signed within minutes, without the total cost being clearly understood.

The habit worth passing on is simple: add up what a commitment will cost over its full duration, not just the amount shown each month.

Without a buffer, the smallest surprise — a repair, a delayed payment — turns into a financial emergency that pushes toward quick, costly decisions.

A small amount set aside regularly, even modest, changes the nature of a surprise: it becomes inconvenient rather than a real problem.

None of these mistakes reflect a character flaw: they happen because no one showed a different way of doing things.

Addressing them one by one, during the year before leaving home, is usually enough to avoid them without an urgent conversation later.