Helping your adult child start a Lifetime ISA

①The LISA mechanics (parent-facing)

If you’ve already read the teen-facing LISA guide, the rules are identical — just from a different vantage point. Key facts:

The £4,000 LISA contribution counts toward the £20,000 overall ISA allowance for the year. So a child maxing the LISA still has £16,000 of allowance available for a Cash or S&S ISA alongside.

②How parental gifting into a child's LISA works

Once the child is 18, only they can open the LISA — their name, their National Insurance number, their identity verification. Parents cannot open it on their behalf.

Once open, anyone can contribute, but the rules around how the contribution is treated for tax matter:

• Contributions from parents are gifts. They're subject to UK Inheritance Tax rules if the parent dies within 7 years (see the inheritance guide).
• Every parent can give £3,000/yr tax-free under the annual gift exemption.
• Wedding gifts to a child get an additional £5,000 exemption.
• Gifts from regular income (not capital) can be unlimited if they meet HMRC's "normal expenditure out of income" rules.

Practically: a parent paying £4,000/yr into a child's LISA for 5 years uses £20,000 of gifting, well within most parents' lifetime gift exemptions if no other large gifts are flowing.

③First home or retirement? Help your child decide

The LISA has two legitimate uses, and the choice can be made years after opening:

First-home use.

• Property up to £450,000 (cap frozen since 2017)
• Buying with a mortgage
• First-time buyer (never owned a UK or overseas property)
• LISA open for at least 12 months

Retirement use.

• Withdraw after age 60 (tax-free)
• No property cap, no first-time requirement

If neither happens and the child withdraws for any other reason, the 25% withdrawal charge applies. The maths is sneaky:

• Pay in £1,000 → bonus £250 → pot £1,250
• Withdraw £1,250 early → charge 25% of £1,250 = £312.50
• You receive £937.50 — £62.50 less than you originally put in

④The £450,000 property cap and what to do about it

The cap has been frozen since LISA launched in 2017, despite house-price inflation. In 2026, the cap excludes:

• Most central London flats above 1-bed
• Much of the Cambridge/Oxford/St Albans commuter belt
• Edinburgh New Town, parts of Glasgow West End
• Average semi-detached homes in many SE England towns

If your child is likely to buy in an expensive area:

• Encourage some LISA contributions (the bonus is valuable for the deposit savings)
• But cap the LISA at, say, £2,000/yr so the gold-handcuffs effect is small if they need to complete on a £500k+ property
• Run the rest as a normal Stocks & Shares ISA — same tax wrapper, no property cap, no penalty

⑤Practical parent gifting strategy

A simple five-year plan if the child is 18 and starts working:

1. Year 1: Child opens LISA. Parent gifts £4,000 (uses £3,000 annual exemption + £1,000 of lifetime gifting capacity). Bonus £1,000 lands.
2. Year 2: Parent gifts £4,000 again. Bonus £1,000. LISA balance now ~£10,500 with growth.
3. Year 3–4: Same pattern. LISA balance ~£22,000 by end of year 4.
4. Year 5: Child contributes their own £4,000 from job income (parental gifting capacity used up for the moment). Bonus £1,000.
5. End of year 5: Pot ~£28,000–£32,000. Enough deposit for most regional first homes under £450k.

Total parental gifting: £16,000 over 4 years. Total government bonus: £5,000. Total child contribution: £4,000.