Methodology | PlatformCompare

How PlatformCompare calculates platform fees and ranks investment platforms.

Updated 15 April 2026

How we calculate fees

Platform fee

We support four fee models, detected automatically from the platform’s data:

Tiered percentage (HL, Fidelity): Each portion of your portfolio is charged at the rate for that tier. For example, HL charges 0.45% on the first £250,000, then 0.25% on the next £750,000. A £300,000 portfolio pays: (£250,000 × 0.45%) + (£50,000 × 0.25%) = £1,125 + £125 = £1,250.

Simple percentage with cap (AJ Bell, Vanguard): Portfolio × percentage rate, capped at a maximum. AJ Bell caps ISA ETF fees at £42/year.

Flat fee (Interactive Investor, Freetrade): A fixed annual amount regardless of portfolio size.

Zero fee (InvestEngine, Trading 212): No platform charge.

Dealing fees

Dealing fees are calculated as:

dealing cost = max(0, annual trades − free trades) × cost per trade

Interactive Investor includes 12 free trades per year in their monthly subscription. Additional trades cost £5.99 each.

Total annual cost

total = platform fee + dealing fees

Rounded to the nearest pound.

What we don’t include

Data sources

All fee data is sourced directly from each platform’s charges page. Source links are shown on every platform page. We update data when platforms publish changes.

Limitations

Last updated: April 2026