Starting to invest for a child early is one of the most powerful financial moves a parent or grandparent can make. Even modest monthly contributions, compounded over 18 years, can grow into a life-changing sum. But UK tax rules around children’s investments are specific and sometimes counter-intuitive. This guide covers the three main options and how to choose between them.
Why Invest for Children?
- Compound growth over decades — Money invested at birth has 18+ years to grow before the child can access it
- Teach financial literacy — A visible investment pot helps children learn about money early
- Reduce future reliance — A lump sum at 18 can fund university, a house deposit, or a business
- Tax efficiency — Children have their own tax allowances, which most don’t use
Option 1: Junior ISA (JISA)
A Junior ISA is the most popular way to invest for children in the UK. It works like an adult ISA — money grows completely tax-free — but it’s held in the child’s name and locked until they turn 18.
How it works
- Annual allowance: £9,000 per tax year (2025/26)
- Two types: Cash JISA or Stocks & Shares JISA (or split between both)
- Access: Locked until the child turns 18 — no early withdrawals
- Who controls it: A parent or legal guardian opens it; someone else (grandparent, family friend) can also contribute
- Tax on growth: None — interest, dividends, and capital gains are all tax-free
- Tax on withdrawal: None — the child receives the full amount at 18
Cash JISA vs Stocks & Shares JISA
| Feature | Cash JISA | Stocks & Shares JISA |
|---|---|---|
| Returns | Interest (typically 3-5%) | Market returns (historically 7-8% over long periods) |
| Risk | Capital guaranteed (within FSCS limits) | Value can fall as well as rise |
| Best for | Short-term goals, risk-averse families | Long-term growth (10+ years) |
| Typical providers | High street banks, NS&I | Vanguard, Hargreaves Lansdown, AJ Bell |
Tip: If the child won’t need the money for 10+ years, a Stocks & Shares JISA almost always outperforms cash over the long run.
The £100 rule for parents
If a parent contributes to a JISA and the child’s total income (including interest and dividends) exceeds £100, that income is taxed as the parent’s — not the child’s. This mainly affects large cash gifts from parents into high-interest accounts. For most JISA contributions this isn’t an issue, but it’s worth knowing if you’re depositing very large sums.
Option 2: Child Pension (SIPP)
A Junior Self-Invested Personal Pension (SIPP) is a pension opened for a child. It’s less well-known than the JISA, but it offers a unique advantage: tax relief on contributions.
How it works
- You contribute: Up to £2,880 per tax year
- Government adds tax relief: 20% automatically, boosting £2,880 to £3,600
- Access: Locked until the child is 57 (rising from 55 under current rules)
- Who controls it: A parent or guardian opens and manages it until the child is 18
- Tax on growth: None inside the pension wrapper
- Tax on withdrawal: 25% can be taken tax-free; the rest is taxed as income
Why consider a child pension?
- Tax relief is free money — The government adds £720 for every £2,880 you put in
- Extraordinary time horizon — Money invested at birth has 57+ years to compound
- No inheritance tax (IHT) implications — Pension contributions are generally outside your estate
- Long-term retirement boost — Even small amounts grow enormously over 50+ years
Example growth
£3,600 per year invested in a child’s SIPP from birth at 7% average annual growth:
| Age | Approximate Value |
|---|---|
| 10 | £52,000 |
| 18 | £134,000 |
| 30 | £350,000 |
| 57 | £2,100,000+ |
That’s from just £2,880 net of your own money per year. The tax relief and decades of compounding do the heavy lifting.
The catch
The child can’t access the money until 57. This makes a SIPP unsuitable if you want the money to help with university fees or a first home — use a JISA for those goals.
Option 3: Bare Trust / General Investment Account
A bare trust is a simple legal arrangement where you hold investments on behalf of a child. It’s not a tax wrapper — it’s a general investment account in the child’s name with some trust scaffolding.
How it works
- No contribution limit — You can invest as much as you like
- Flexible access — Money can be withdrawn before the child turns 18 (with proper trust administration)
- Child’s tax allowances — Income and gains are taxed as the child’s, using their Personal Allowance, Capital Gains Tax allowance, and Personal Savings Allowance
- IHT implications — Contributions may be treated as gifts from the parent and could fall within the parent’s estate for IHT purposes if the parent dies within 7 years
Tax implications
- Income tax: The child’s own £12,570 Personal Allowance applies to any income
- Capital gains tax: The child has their own CGT annual exempt amount
- Parent’s income rule: If the money came from a parent and produces income over £100/year, the parent pays tax on it (same as with JISAs)
When to use a bare trust
- You want maximum flexibility on when and how the child accesses the money
- You’re comfortable managing a trust or paying an adviser to do so
- You want to invest more than the JISA annual limit
- You accept the IHT and administrative complexity
Risks to consider
- More administrative burden than a JISA or SIPP
- Potential IHT complications if the parent dies within 7 years
- The child receives the money unconditionally at 18 — you have no control over how they use it
- Less consumer protection than regulated ISA or pension products
Comparison Table
| Feature | JISA | Child SIPP | Bare Trust / GIA |
|---|---|---|---|
| Annual limit | £9,000 | £2,880 (£3,600 with tax relief) | Unlimited |
| Tax relief | None | 20% (government boosts contributions) | None |
| Access age | 18 | 57 (rising from 55) | Anytime (trustee must manage) |
| Tax on growth | None | None | Child’s tax allowances |
| Tax on withdrawal | None | 25% tax-free, rest taxed as income | Child’s tax allowances |
| IHT implications | None (child’s own account) | None (outside estate) | May be within parent’s estate |
| Admin complexity | Low | Low | Medium-high |
| Best for | University, house deposit, flexibility | Long-term retirement, tax-free compounding | Large gifts, maximum flexibility |
Worked Example: £200/Month in a JISA From Birth
If you invest £200 per month from the day a child is born into a Stocks & Shares JISA, assuming 7% average annual growth:
| Age | Total Contributed | Estimated Value |
|---|---|---|
| 5 | £12,000 | £14,400 |
| 10 | £24,000 | £34,500 |
| 15 | £36,000 | £63,200 |
| 18 | £43,200 | £91,500 |
You contribute £43,200. The account is worth over £91,000. That’s nearly £48,000 in tax-free growth — and the child can use the entire amount for university, a first home, or whatever they choose.
If you also maximised a child SIPP at the same time, adding £240/month (which with tax relief becomes £300/month), the combined pot at 18 would be significantly higher — and the pension portion would have over 57 more years to grow.
Tax Rules to Know
The £100 income rule
If a parent gifts money to a child (in a JISA, savings account, or bare trust) and the total income from that money exceeds £100 per tax year, all the income is taxed as the parent’s — not the child’s. This prevents parents from shifting large income-producing assets to children to use their lower tax allowances.
- £100 threshold applies per parent, per child
- Applies to interest, dividends, and other income from a parent’s gift
- Does not apply to gifts from grandparents or non-parents (though anti-avoidance rules can still apply in some cases)
Children’s personal allowances
- Personal Allowance: £12,570 (no income tax on the first £12,570)
- Personal Savings Allowance: £1,000 (basic rate) or £500 (higher rate)
- Dividend Allowance: £500
- Capital Gains Tax annual exempt amount: £3,000
For most children, these allowances are more than enough to shelter any investment income — which is why a bare trust or GIA can be surprisingly tax-efficient.
Which Option Is Best for You?
Choose a JISA if:
- You want a simple, tax-free account for university or a first home
- You prefer low admin and straightforward access at 18
- You want to contribute up to £9,000 per year
Choose a child SIPP if:
- You’re focused on long-term retirement wealth for the child
- You want the benefit of tax relief on contributions
- You don’t need the money until the child is 57+
Choose a bare trust / GIA if:
- You want maximum flexibility and no contribution limits
- You’re comfortable with trust administration
- You want the child to access money before 18
Use a combination if:
- You want both medium-term flexibility (JISA) and long-term compounding (SIPP)
- Many families contribute £9,000 to a JISA plus £2,880 to a SIPP — total £11,880/year in tax-efficient wrappers
Getting Started
- Open a JISA — Most platforms let you open one online in minutes. Vanguard, Hargreaves Lansdown, and AJ Bell are popular choices with low fees.
- Set up a monthly contribution — Even £50-£100/month grows substantially over 18 years
- Consider a SIPP alongside — If you can afford more, the tax relief on a child pension is too valuable to ignore
- Review annually — Check your investment allocation as the child gets older, shifting toward lower risk as the access date approaches
Starting early is the single biggest advantage you can give a child’s investments. Whether it’s £50 a month or £500, the power of 18+ years of compound growth turns consistent contributions into a meaningful sum.