What makes a great pension platform?
A pension platform is the technology layer that holds your SIPP, lets you choose investments and reports your performance. The four things that separate the best from the rest are platform charges, dealing costs, fund range and the quality of the app and research tools. In 2026 the gap between providers is mostly about fees on larger pots.
| Platform | Platform fee (funds) | Fund choice | Best for |
|---|---|---|---|
| Vanguard Investor | 0.15% (capped £375/yr) | ~85 Vanguard funds | Passive, low-cost simplicity |
| AJ Bell | 0.25% (capped £120/yr shares) | 4,000+ funds, full market | Mid-size pots, app users |
| Hargreaves Lansdown | 0.45% (capped £200/yr shares) | 3,000+ funds, deepest research | Service and breadth |
| interactive investor | £12.99/mo flat fee | 40,000+ instruments | Large pots (£100k+) |
| Fidelity | 0.35% (under £25k) | 3,000+ funds | Beginners with smaller pots |
Percentage vs flat fees
Percentage-fee platforms like Vanguard, AJ Bell and HL are cheapest for smaller pots because you pay in proportion to what you hold. Once a pot passes roughly £100,000–£150,000, interactive investor's flat £12.99 a month (about £156 a year) usually wins because the charge stops growing with your pot. On a £300,000 pot, HL would charge £1,350 a year against ii's £156 — a difference that compounds enormously over a 20-year retirement.
App and tools
Hargreaves Lansdown and AJ Bell both have polished, highly rated apps with strong research and fund screeners. Vanguard's app is deliberately minimal — ideal if you just want to buy a single global tracker and leave it. interactive investor's interface is more functional than slick but covers a vast instrument range.
Verdict
For most people building a pension, Vanguard offers the lowest-cost route if you are happy holding Vanguard funds only. AJ Bell is the best all-rounder for whole-of-market choice at a fair price. Choose interactive investor once your pot is large, and Hargreaves Lansdown if you value service and research above headline cost. Compare the underlying SIPPs in our best SIPP providers guide and the wider field in our best pension providers guide.