The Top 5 UK Investment Platforms, Compared

Choosing an investment platform feels like it should be simple — they're all doing roughly the same job, moving your money into funds and shares — but the fee structures differ enough that the "wrong" choice can quietly cost you hundreds of pounds a year once your portfolio grows. There's no single "best" platform; the right one depends on how much you're investing, how often you trade, and how much you value things like research tools versus a rock-bottom fee.

Plenty of platforms exist beyond these five, but these are the ones that come up most often in UK personal finance conversations — between them they cover every major fee model (percentage, capped, flat, and free) and every portfolio size from a first £100 investment to a seven-figure SIPP.

If you're still deciding which account type — ISA, SIPP, LISA, or GIA — to hold your investments in before picking a platform for it, ISA vs LISA vs GIA: A Plain-English Guide covers that groundwork first.

Quick disclaimer: fees and features change, sometimes without much notice — several of the platforms below changed their entire pricing structure earlier in 2026. Always check the provider's own site for current pricing before committing. This isn't personal financial advice — it's a starting point for your own comparison.

The fee models, briefly

UK platforms generally charge one of three ways:

• Percentage-based fees — a small percentage of your total portfolio value each year, sometimes capped at a maximum. Cheap on a small portfolio, more expensive as it grows unless a cap kicks in.
• Flat monthly fees — a fixed amount regardless of portfolio size. Look expensive on a small pot, become much better value as your investments grow.
• Free — no platform fee at all, usually recouped elsewhere (foreign exchange fees, interest on uninvested cash, or a narrower product range).

Which model wins depends entirely on your portfolio size — a percentage fee that looks trivial at £5,000 can be meaningfully more expensive than a flat fee once you're past £40,000–£50,000.

The platforms

Hargreaves Lansdown

The largest and most established platform in the UK, and the one most people have heard of even if they've never invested.

Strengths: the widest fund research and selection, a genuinely excellent app and website, and customer service that's consistently rated above its competitors — you can actually get a human on the phone.

Trade-off: HL's fee structure is genuinely more complex than its competitors' — funds are charged a tiered percentage (0.35% up to £250,000, stepping down at higher tiers), while shares and ETFs are charged separately and capped, with the exact cap differing between ISA and SIPP. On top of the platform fee, buying or selling a fund now carries its own £1.95 dealing charge. None of this makes HL expensive exactly, but it does mean the "one simple number" other platforms can quote doesn't really exist here — check HL's own pricing page against your specific mix of funds vs. shares before assuming a figure.

Best for: investors who value research depth and support over shaving off the last few pounds of fees, especially those with SIPPs and multiple account types who benefit from everything being in one well-supported place.

Trading 212

A commission-free app-based platform that's become one of the most popular entry points for newer UK investors, particularly for ISA investing.

Strengths: no platform fee and no dealing charges on its ISA or general investment account, fractional shares (so you can invest small amounts in expensive stocks), and a low foreign exchange fee when buying overseas shares — among the cheapest of any platform to actually use.

Trade-off: lighter on research and educational tools compared to HL or AJ Bell, and no SIPP offering, so it doesn't cover your full account needs on its own.

Best for: cost-conscious ISA investors, especially those who want to start small or invest regularly without fees eating into contributions — for most people starting out with a portfolio under roughly £20,000, this is genuinely difficult to beat on pure cost.

AJ Bell

Sits comfortably between HL's premium positioning and the free apps — a solid, broad-range platform without the top-tier price tag.

Strengths: funds are charged 0.25%, stepping down to 0.10% between £250,000–£500,000 and free above that; shares and ETFs are charged separately but capped — £3.50/month (£42/year) in an ISA, £10/month (£120/year) in a SIPP. That capped-shares structure makes AJ Bell genuinely competitive with HL for share/ETF-heavy portfolios, at a noticeably lower cap. Regular monthly investing dealing is free. A full suite of account types — SIPP, ISA, LISA, JISA, and general investing — genuinely one of the most complete "all your accounts in one place" options.

Trade-off: not the cheapest at any single price point, but reliably mid-market and dependable across the board.

Best for: investors who want more choice and flexibility than the zero-fee apps offer, without paying HL's premium — particularly those who hold a mix of funds and individual shares/ETFs and want both fee structures capped sensibly.

Vanguard UK

Vanguard's own platform, built primarily to hold Vanguard's own index funds — which happen to be some of the lowest-cost funds available.

Strengths: a straightforward, low-drama setup — 0.15% annually, capped at £375/year once your holdings pass £32,000. Ideal for the "set up a direct debit into a global index fund and don't touch it" approach that a lot of long-term FIRE investing is built around.

Trade-off: limited to Vanguard's own fund range — you can't hold other providers' funds or individual shares here. Also worth knowing: below £32,000, Vanguard charges a flat £4/month (£48/year) minimum instead of the percentage rate — on a £10,000 portfolio that works out to an effective 0.48%, over three times the headline 0.15% figure, so it's noticeably less competitive for smaller pots than the headline rate suggests.

Best for: hands-off, buy-and-hold index investors with £32,000+ already invested who don't need fund choice beyond what Vanguard already offers.

Interactive Investor (ii)

A flat-fee platform aimed squarely at investors with meaningful portfolio size, where percentage fees start to bite — and one that overhauled its entire pricing model in February 2026.

Strengths: a single monthly fee now covers your ISA, SIPP, and GIA together — a real change from the old structure, where each account type was charged separately and having both an ISA and a SIPP could roughly double your cost. The Core plan (£5.99/month) covers portfolios up to £100,000 across all your accounts combined; Plus (£14.99/month) removes that cap for larger portfolios; Premium (£39.99/month) adds extra research and tools on top. Once your combined portfolio passes roughly £48,000, the Core plan's flat fee typically already beats Vanguard's percentage-based charge.

Trade-off: at smaller portfolio sizes, the flat fee is proportionally more expensive than percentage-based alternatives — this only pays off once you've built up a reasonable pot, though the new all-accounts-in-one-fee structure has pushed that break-even point meaningfully lower than it used to be for anyone running both an ISA and a SIPP.

Best for: investors with £50,000+ across their accounts, especially anyone holding both an ISA and a SIPP who'd have paid two separate fees under the old structure.

Side-by-side snapshot

How to actually decide

Rather than chasing the single cheapest platform, it's worth asking three questions: Do you need a SIPP as well as an ISA, or just one — and if both, does the platform charge for them separately or together? Roughly how large is your portfolio likely to be in 2–3 years, not just today — since that determines whether a percentage, capped, or flat fee wins? And how much do you value research tools and support versus just wanting the lowest possible cost?

There's also nothing stopping you from splitting across platforms — plenty of investors hold, say, a Vanguard ISA for hands-off index investing and a Trading 212 account for smaller, more active picks. Since April 2024, you're free to open ISAs with multiple providers in the same tax year, as long as your total contributions across all of them stay within the £20,000 annual allowance.

Fee figures above were checked against each provider's current published pricing at the time of writing. Several of these platforms changed their entire fee structure earlier in 2026, so treat any specific number here as a starting point, not gospel — confirm on the provider's own site before committing.