A Junior SIPP lets you contribute up to £2,880 a year into your child's pension — HMRC automatically adds basic-rate tax relief (25% on top of what you pay, or 20% of the total), topping it up to £3,600. That's £720 of free money every year, locked away until they're 57, growing for decades.
Three things make Junior SIPPs unusually powerful
You contribute up to £2,880 and HMRC adds 20% tax relief automatically, bringing the total to £3,600. This happens even though your child has no income and pays no tax.
£720 free from HMRC on a full contributionA newborn can't access the pension until they're 57. That's potentially 57 years of compound growth on every pound — including the government's contribution. Time is the most powerful variable.
Up to 57 years of tax-free growthFor parents with larger estates, contributing to a child's Junior SIPP moves wealth out of your estate now — while you're alive — into a structure the child cannot access or spend prematurely.
Reduces your taxable estate todayAdjust the sliders to model your child's pension at retirement
Two very different jobs — many families use both
| Junior SIPP | Junior ISA | |
|---|---|---|
| Annual limit | £2,880 paid in (£3,600 with relief) | £9,000 |
| Government top-up | 20% tax relief | None |
| Tax on growth | None while invested | None |
| Child can access | At 57 (from April 2028) | At 18 |
| Tax on withdrawal | 25% tax-free, rest taxed as income | None |
| Best for | Retirement — the longest compounding runway | University, a first home, early adulthood |
Parents or grandparents with surplus cash looking to reduce their estate. Entrepreneurs who've sold a business and want to deploy capital tax-efficiently. Higher earners whose ISA and pension allowances are already maxed. Anyone who wants to give a child a financial foundation that compounds quietly in the background for decades, completely out of reach until it's truly needed.
Einstein reportedly called compound interest the eighth wonder of the world: "He who understands it, earns it; he who doesn't, pays it." A Junior SIPP is perhaps the purest expression of this idea available to a UK investor.
£3,600/year from birth to age 18 — the maximum contribution window — growing at 8% produces a pension pot worth about £2.9m at 57 in nominal terms, from £51,840 of your own money and £12,960 of HMRC's — £64,800 in all. The rest is time.
At 18 the Junior SIPP converts automatically into a regular SIPP in the child's name — and the story doesn't have to stop there. During any period the grown-up child has little or no earned income (university, further study, travel, early career breaks) a parent or grandparent can continue contributing up to £2,880 a year, still attracting the same 20% government top-up to £3,600. The runway keeps extending, and every extra year at this stage of the compound curve is disproportionately powerful.
The money is locked until retirement — it cannot fund university, a first home, or early career. It's not suitable if you may need the capital back. Junior SIPPs are regulated products; you'll need a broker or platform to open one. Rules on contribution limits and access ages can change.
From April 2027, unused pension pots will form part of a person's estate for IHT. This affects the child's pension when they eventually die — not your contribution now. Your gift into the Junior SIPP is out of your estate today, which remains the key estate planning benefit.