Junior ISA guide: how to save for your child's future

SYMFamily Finance

A Junior ISA (JISA) is one of the most powerful financial gifts parents can give a child. Start at birth, contribute consistently, and by age 18 your child could have a significant sum for university, a house deposit, or simply a head start in adult life. Here's everything you need to know.

Junior ISA Basics

A Junior ISA is a tax-free savings account for children under 18 living in the UK. The 2026/27 allowance is £9,000 per child per tax year. No tax is paid on interest, dividends, or growth inside the account. At age 18, the JISA automatically converts to an adult ISA and the child gains full control.
  • £9,000 annual allowance per child (2026/27)
  • Tax-free interest, dividends, and growth
  • Opens from birth, accessible at age 18
  • Available as Cash JISA or Stocks & Shares JISA

Cash JISA vs Stocks & Shares JISA

For a child with 10–18 years before accessing the money, a Stocks & Shares JISA almost always outperforms a Cash JISA over the long term. Historical global stock market returns of 7–10% per year dwarf the best Cash JISA rates. Volatility matters less over longer time horizons — a market dip at age 10 is irrelevant when the money isn't needed until 18.

How Much Could It Grow To?

The power of compound growth over 18 years is substantial:
  • £50/month for 18 years at 7% avg: ~£24,000
  • £100/month for 18 years at 7% avg: ~£48,000
  • £200/month for 18 years at 7% avg: ~£96,000
  • Full £9,000/year for 18 years at 7% avg: ~£340,000

Who Can Contribute?

The account is managed by a parent or guardian, but anyone can pay into it — grandparents, other family members, friends. This makes JISAs perfect for birthday and Christmas gift requests. Simply give people the JISA details and ask them to contribute instead of buying toys. Small contributions from multiple family members compound significantly over 18 years.

Choosing a Provider

For a Stocks & Shares JISA, look for low platform fees and access to global index funds. Leading providers include Vanguard (very low fees, excellent index funds), AJ Bell (wider fund selection), and Fidelity. Avoid high-fee products — a 1% platform fee versus a 0.15% fee on £50,000 accumulated costs £425/year.
Can my child access the money before 18?
No — JISA funds are locked until the child turns 18. This is actually a feature for many parents: it prevents the money being spent before the child has the financial maturity to use it wisely.
What if my child already has a Child Trust Fund?
You can transfer a Child Trust Fund to a Junior ISA. This is usually beneficial as CTF providers often have higher charges and fewer investment options than modern JISA providers. Contact a JISA provider to initiate the transfer.
  • Junior ISA
  • JISA
  • children's savings
  • UK
  • parents
  • investing

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