AJ Bell Junior ISA Review 2026/27: £30 Cap, £9,000 Allowance, and Why Two Rivals Are Free

AJ Bell's published Junior ISA charges split into two halves. The first is the platform charge — what you pay AJ Bell for holding the investments. The second is the dealing charge — what you pay each time you buy or sell.

On the platform side, the headline rate is 0.25% a year of the value held. That rate applies to both shares and funds. The crucial difference: the shares portion is capped at £2.50 a month (£30 a year), while the funds portion is uncapped at the JISA tier. That means a £100,000 shares-only JISA pays £30 a year. A £100,000 funds-only JISA pays £250 a year. The same total balance, the same wrapper — fee structure is the lever that decides which is cheaper.

Dealing is where it gets specific. Share trades cost £5.00 each, dropping to £3.50 if you placed 10 or more share deals across all your AJ Bell accounts in the previous calendar month — unlikely inside a JISA you're feeding monthly. Fund trades are £1.50. Regular investing — a monthly direct-debit drip from £25 — is free, which is the path most JISA contributors should be using anyway. Withdrawals at age 18 are free.

For a deeper line-by-line breakdown of AJ Bell's fee schedule across all account types, see our Bestinvest vs AJ Bell fee comparison — the same structure applies inside the JISA, with the lower JISA-specific cap.

The chart shows the fee paid on a £20,000 JISA. The 100%-shares row is £30 because it hits the cap. The 50/50 row is £30 (capped shares portion) plus £25 (uncapped 0.25% on £10k of funds), so £55. The 100%-funds row is £50 (0.25% on £20k). The cap quietly favours portfolios with a meaningful equity ETF or investment trust component.

AJ Bell prices its adult ISA at the same 0.25% rate but with a £3.50/month cap on shares. The Junior ISA caps it at £2.50/month — a 29% reduction. AJ Bell does not advertise this as a JISA differentiator and many comparison tables ignore it.

In practice the difference is small in absolute terms — £12 over a tax year — but it compounds in two interesting ways. First, a JISA fed for 18 years pays the cap for most of those years (any pot above ~£12k of shares hits the cap). Over the full 18-year horizon, that's a £216 saving versus paying the adult cap. Second, the cap means the percentage drag of the platform fee falls every year as the pot grows. On a £100,000 JISA held entirely in shares, AJ Bell's effective annual platform fee is 0.03% — vanishingly small. We've covered the headline cap mechanics in detail in our piece on AJ Bell's 0.25% fee cap and what it actually costs.

Funds-heavy JISAs do not benefit from the cap. If you intend to hold AJ Bell's Ready-Made Portfolios (multi-asset funds) or third-party OEICs, the 0.25% scales linearly. A £100,000 funds-only JISA pays £250 a year — and the next section explains why two rivals charge nothing at all for the same.

The platform fee is only part of the bill. Every fund inside the JISA carries an Ongoing Charges Figure (OCF) that the fund manager — not the platform — charges. A global equity tracker typically runs 0.10–0.25% OCF; an actively managed fund 0.50–0.95%. Add this to the platform fee to see the true annual drag.

The headline fact: Hargreaves Lansdown and Fidelity both charge a 0% annual account fee on Junior ISAs. Hargreaves also charges no online dealing fees inside the JISA. AJ Bell's JISA is the priciest of the three on the platform line — though its absolute cost stays modest thanks to the cap. For the wider Hargreaves proposition (adult ISA, SIPP, fund choice) see our Hargreaves Lansdown platform review; for Fidelity, our Fidelity Personal Investing review.

For a £20,000 JISA invested in a global equity ETF (OCF 0.20%):

• Hargreaves Lansdown: £0 platform fee + £40 OCF = £40 a year (0.20%)
• Fidelity: £0 platform fee + £40 OCF = £40 a year (0.20%) — but Fidelity does not allow direct ETF or share dealing inside a JISA, so the comparison is funds-only at Fidelity
• AJ Bell: £30 platform fee (capped) + £40 OCF = £70 a year (0.35%)

For an £80,000 JISA invested in an actively-managed multi-asset fund (OCF 0.75%):

• Hargreaves Lansdown: £0 + £600 OCF = £600 a year (0.75%)
• Fidelity: £0 + £600 OCF = £600 a year (0.75%)
• AJ Bell: £200 platform fee + £600 OCF = £800 a year (1.00%)

The pattern: Hargreaves is the headline-cheapest because it offers full investment range — funds, shares, ETFs, investment trusts, bonds — at zero platform fee. Fidelity matches on price but restricts the universe to funds and Fidelity-curated equivalents. AJ Bell is the only one of the three with a platform fee. Across an 18-year JISA at six-figure balances, the cumulative AJ Bell premium runs into the high hundreds of pounds. The honest answer is that AJ Bell loses on price.

Three scenarios make the £30/year defensible.

You're already an AJ Bell customer for your own ISA or SIPP. Account consolidation has real value. One login, one set of statements, one help-desk number, and the ability to hold the JISA alongside the rest of the family's accounts inside a single platform interface matters to a meaningful number of people. AJ Bell's Ready-Made Portfolios work the same way across adult and JISA accounts. For the broader AJ Bell platform proposition — adult dealing fees, SIPP charges, account range — see our AJ Bell platform review.

You actively prefer AJ Bell's research, app, or service. AJ Bell is consistently ranked at the top of UK investment-platform reviews on customer service. It has been Which? Recommended for eight consecutive years (2019-2026 per AJ Bell's own published claim). The dealing app is well-regarded. If you've used Hargreaves and disliked it (some find the interface dated), or if you've tried Fidelity and found the funds-only restriction limiting, AJ Bell is the obvious middle ground.

You want full investment breadth and the £30 cap reassures you on the upside. Hargreaves offers the same breadth at zero platform fee, so this scenario is narrower than it looks. The honest reading: if you've shortlisted AJ Bell and Hargreaves and you can't choose, Hargreaves is cheaper, but the gap is £30/year. If service quality, app, or research preference points to AJ Bell, the £30 is not material on a long-horizon JISA.

What the £30 specifically does not buy you: lower OCFs (those are set by fund managers, not platforms), better tax treatment (JISA rules are HMRC-set and identical across providers), or higher returns (the wrapper does not affect investment performance). It buys you AJ Bell's service, brand, and ecosystem — which has value, but it is not free.

The investment universe matters because it dictates which providers you can shortlist. AJ Bell's JISA accepts:

• Funds — over 2,000 unit trusts and OEICs, including all the major index funds and multi-asset ranges
• Shares — UK and international equities, including individual FTSE 100 stocks like Shell, Barclays, and AstraZeneca
• ETFs — passive index trackers like Vanguard FTSE All-World or iShares Core MSCI World, which most parents will want as a JISA core
• Investment trusts — closed-ended funds like Scottish Mortgage or City of London, often cheaper than equivalent open-ended funds and traded on exchange
• Gilts and bonds — useful as the JISA approaches the child's 18th birthday and you want to derisk
• AJ Bell own-brand funds — including Ready-Made Portfolios at 0.31% OCF

Fidelity's JISA, by contrast, is funds-only — no direct shares, no investment trusts, no individual ETFs (only Fidelity-curated fund-of-fund equivalents). Hargreaves matches AJ Bell's full breadth at zero account fee, which is why Hargreaves wins on the simple price-vs-range axis.

For most JISA holders, the breadth question is moot. The textbook approach is to hold a single global equity index fund or ETF for 18 years and add nothing else. Any of the three providers handles that adequately. Breadth only matters if you actively want to mix wrappers (some active funds, some ETFs, some investment trusts, gilts as the child approaches 18) — and even then, Hargreaves does the same job at £0. For the equivalent fund-side breakdown on Fidelity, see our Fidelity ISA and SIPP fees article.

The JISA's structural advantage is the time horizon: 18 unbroken years of tax-free compounding inside a wrapper your child cannot touch. That is materially longer than most adult ISAs see before being raided for a house deposit or a car. For a deeper look at what this kind of disciplined contribution can build, see our Junior ISA strategy piece on £9,000 a year.

The £9,000 allowance has been frozen since 2020/21 and shows no sign of being raised. Real-terms, the cap is shrinking — UK CPI per the ONS has run roughly 25% cumulatively over that frozen period, so today's £9,000 buys what £7,200 did in 2020. Plan accordingly: full-allowance JISAs are getting easier to fund (in nominal terms) every year.

Real-world fees, contribution timing, and market sequence affect outcomes materially. The 6% real assumption is a conservative long-run global equity average; some 18-year periods have delivered considerably more, others less. Use the GiltEdge ISA growth calculator to model your own assumptions, and see our main ISA hub for the broader rules around contributions, transfers, and the adult £20,000 limit.

On AJ Bell specifically: even at the worst-case £200/year platform fee on a fully-funds £80k JISA, the cumulative cost over 18 years sits around £3,600. Hargreaves and Fidelity charge nothing for the same. Three-and-a-half thousand pounds compounded over a working lifetime in the child's later adult ISA is not nothing — but it is also not catastrophic on a six-figure JISA. The right way to frame the decision: pick the platform whose service and breadth you actually want, accept the cost difference if it leans toward AJ Bell.

Only a parent or legal guardian can open a Junior ISA. The child must be UK-resident and under 18, and cannot already hold a Child Trust Fund (CTFs can be transferred in — they cannot coexist with a JISA).

The AJ Bell process is online, takes around 10 minutes, and requires the child's date of birth and National Insurance number if they have one (under-16s usually do not — AJ Bell will collect it later). You'll need the child's birth certificate or passport details. Once open, the account belongs to the child but is managed by the named contact (you) until they turn 16, after which the child can take over administrative control. Withdrawals remain blocked until 18.

Funding tips that apply regardless of provider:

• Set up regular investing from £25/month — it removes both the timing decision and the dealing fee. Pick a global equity index fund (low OCF) for the core.
• Time lump sums to the start of the tax year (6 April) — gives the contribution maximum time to compound inside the wrapper.
• Don't forget grandparents — anyone can contribute, as long as the £9,000 cap across all sources isn't breached. Grandparent contributions also fall within the £3,000 annual gift exemption for IHT purposes.
• Verify the cap if you switch from another platform — transfers in do not use the £9,000 allowance, but contributions made elsewhere in the same tax year do count toward it.

One thing AJ Bell does not offer: a Cash JISA equivalent — the AJ Bell wrapper is Stocks & Shares only. If your child is 16 or 17 and you want to derisk into a fixed-rate Cash JISA before the 18th birthday, you'll need to transfer out to a building society — adding admin and a few weeks of out-of-market time. Coventry, Yorkshire, and Skipton building societies all offer competitive Cash JISA AERs. FCA-registered, FSCS-protected up to £85,000 per investment account — this is the investment cover, not the £120,000 deposit cover that applies to Cash ISAs at banks.

This article is for informational purposes only and does not constitute financial advice. You should seek independent financial advice before making any investment decisions. Tax treatment depends on individual circumstances and may change. GiltEdge is not regulated by the Financial Conduct Authority (FCA). Junior ISA rules and the £9,000 annual allowance are based on HMRC guidance for the 2026/27 tax year. For impartial guidance, see MoneyHelper. Provider fees and product features were verified against published sources on 2 May 2026 — always check the provider's own current charges schedule before opening an account.