Both are FCA regulated and FSCS protected. The real differences are fees, investment range and how each platform feels to use. Here is the honest comparison.
Fees verified July 2026. Capital at risk. Information, not financial advice.
Portfolios above roughly £60k where a flat fee beats percentage charges.
Investors who want the fullest service, research and support and will pay a premium for it.
| Fee | Interactive Investor | Hargreaves Lansdown |
|---|---|---|
| Platform fee | Core £5.99/month (up to £100k); Plus £14.99/month (no limit); Premium £39.99/month | 0.35% on funds up to £250k (tiered lower above); shares capped at £45/year in an ISA and £150/year in a SIPP |
| Share dealing | £3.99 per trade (£2.99 on Premium) | £6.95 per trade (cut from £11.95 in March 2026) |
| Fund dealing | £3.99 per trade (£2.99 on Premium) | £1.95 per trade (free via regular investing) |
| FX fee | 1.5% on the first £25k, tiered lower above | 1% on the first £5k, tiered lower above |
| Stocks & Shares ISA | Included in the monthly plan | Platform fee applies |
| SIPP | Included in the monthly plan | Platform fee applies |
| Withdrawals | Free | Free |
| Minimum to start | No minimum (£25/month for regular investing) | £25/month or £100 lump sum |
Long-standing customers value the flat fee and the breadth of investments.
The 1.5% headline FX fee and occasional platform outages are the recurring complaints.
Read Interactive Investor reviews on TrustpilotService quality is the recurring theme: phone answered quickly, knowledgeable staff, smooth transfers.
Price. Even after the cuts, reviewers and commentators note cheaper alternatives for the same investments.
Read Hargreaves Lansdown reviews on TrustpilotInteractive Investor charges a flat monthly subscription instead of a percentage. On a £200,000 portfolio, £5.99 a month is a fraction of what percentage-fee platforms charge, which is why ii keeps winning larger DIY investors.
The equation flips for small pots: £71.88 a year on £10,000 is 0.7%, more than almost any rival. Work out your portfolio size first, then decide.
Hargreaves Lansdown is the UK's largest DIY investment platform and leans into service: fast phone support, deep research and every account type you might need. The March 2026 fee cuts made it meaningfully cheaper, with fund fees down to 0.35% and share dealing at £6.95.
It is still rarely the cheapest option. You are paying for service and breadth, so the honest question is whether you will use them. If not, AJ Bell offers similar range for less.
A 0.2% fee difference is worth optimising. Knowing whether you are saving enough in the first place is worth far more. Delphina models your pensions, ISAs and investments and tells you where you actually stand.