Platform Fees vs Fund Fees UK 2026/27 — The Full Split

Two different bills, one total cost

When UK investors talk about "investment fees", they usually mean one number. But it's actually two: the platform fee (what your ISA/SIPP provider charges to hold your investments) and the fund fee (what the fund manager charges to run the fund). Understanding the split is the difference between a well-optimised portfolio and one silently bleeding money.

The platform fee

The platform is the custodian — the online service that holds your ISA, SIPP or GIA. Popular UK platforms and their fee models:

The fund fee (OCF)

Set by the fund provider, not the platform. Deducted daily from fund NAV. Same fund costs the same OCF wherever you hold it.

• Vanguard FTSE All-World UCITS ETF (VWRP): 0.22%
• Vanguard S&P 500 UCITS ETF (VUAG): 0.07%
• iShares Core MSCI World (SWDA): 0.20%
• Vanguard LifeStrategy 80% Equity: 0.22%
• Fidelity Index World: 0.12%

Why the split matters

Platform fees vary widely between providers; fund fees vary widely between funds. Different combinations produce dramatically different total costs. Getting the split wrong is one of the most expensive mistakes UK investors make.

Real UK cost examples on £20,000

Same £20,000, same 30-year horizon at 6% return before fees. The gap between cheapest (£44/year) and most expensive (£280/year) compounds to over £110,000 of terminal wealth difference over 30 years.

Decision rules

• If your holdings are ETF-only: Use InvestEngine or a platform with capped ETF fees like HL.
• If your holdings are fund-only: Vanguard Investor for LifeStrategy, or AJ Bell for broader fund range.
• If your portfolio is over £100k: Interactive Investor's flat fee often wins.
• If you value research and phone support: HL is worth its higher percentage — cap on ETFs limits the damage.

Common mistakes

• Holding a fund on a platform that penalises funds (e.g. Vanguard LifeStrategy at HL — uncapped 0.45%).
• Holding ETFs on a platform that penalises ETFs with high dealing fees.
• Ignoring flat-fee platforms once the pot grows past £75,000.
• Focusing on the OCF alone and ignoring platform fees.
• Choosing an active fund without checking whether the platform fee stacking makes it uneconomic.

Frequently asked questions

Which is bigger — platform fee or fund fee?

Depends on the setup. On a Vanguard tracker at HL, platform fee is often 2x the fund fee. On the same fund at InvestEngine, fund fee is the entire cost.

Can I hold funds and ETFs on the same platform?

Yes — most platforms support both. Just be aware the fee structure often differs: funds may be uncapped percentage, ETFs may be capped.

Is a flat monthly fee always cheaper?

Only once your portfolio is big enough. £5.99/month on £10k is 0.72% — expensive. On £100k it's 0.07% — very cheap.

Do platform fees come out of my ISA allowance?

No. Fees are deducted from your balance but don't count against your £20,000 annual allowance.

How do I calculate my current total fee?

Add your platform fee (% or £) to the OCF of each fund weighted by holding, plus any dealing fees over the year. Under 0.5% total is well-optimised; over 1% deserves review.