Comparison Guide · 2026-07-03
SIPP Flat Fee vs Percentage Fee Platforms UK 2026/27
Flat-fee SIPP platforms charge a fixed pounds-and-pence amount per year (e.g. £120–£300), regardless of how large your pension pot grows, which becomes increasingly cheap as a percentage of a larger fund. Percentage-fee platforms charge a set rate (commonly 0.15%–0.45% per year) of your total pot value, which is cheaper for smaller pots but scales up in cash terms as your pension grows, often without any cap.
At a Glance
| Feature | Flat Fee Platform | Percentage Fee Platform |
|---|---|---|
| Fee structure | Fixed amount per year, sometimes tiered by pot size or account type | Percentage of assets under management, often reducing at higher balance tiers |
| Best for small pots | Can be expensive relative to a small pot (higher % of assets) | Cheap in cash terms for pots under roughly £30,000–£50,000 |
| Best for large pots | Very cheap in percentage terms once the pot exceeds roughly £50,000–£100,000 | Fee grows in cash terms as the pot grows, unless capped |
| Fee predictability | Fully predictable cash cost each year | Cost varies with market performance and contributions |
| Typical range | £120–£300+/year flat, sometimes plus a small per-trade dealing fee | 0.15%–0.45%/year, some platforms cap the percentage fee at a maximum £/year |
| Crossover point | Becomes cheaper than percentage fees once the pot is large enough that % > flat fee | Cheaper below the crossover pot size |
When Flat Fee Platform Wins
- Your pension pot is well above the platform's break-even threshold (commonly £50,000+)
- You want fully predictable annual costs regardless of investment performance
- You hold higher-value, lower-turnover investments (e.g. mostly funds, few trades)
When Percentage Fee Platform Wins
- You are early in your pension-saving journey with a smaller pot
- You want fees to automatically stay proportionate to your pot size
- You value simplicity over optimising for the lowest possible fee at scale
Frequently Asked Questions
At what pension pot size does a flat fee become cheaper than a percentage fee?
This depends on the specific platform's rates, but as a rule of thumb, a flat fee of around £200–£300/year typically becomes cheaper than a 0.35%–0.45% percentage fee once your pot reaches somewhere between £50,000 and £80,000 — always calculate the crossover using your specific platform's published charges, since fee structures vary significantly.
Do percentage-fee SIPP platforms cap their charges?
Some do — several major platforms cap the percentage platform fee at a maximum cash amount per year once your pot exceeds a certain size, which changes the crossover calculation significantly in favour of the percentage-fee platform for very large pots. Always check whether a cap applies before comparing.
Are there other fees besides the platform fee to consider?
Yes — most SIPPs also charge underlying fund management charges (regardless of platform fee structure), and some charge separate dealing fees for buying/selling shares or funds, transfer-out fees, and drawdown administration fees, so compare the total annual cost across all charges, not just the headline platform fee.
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Can I switch SIPP platforms if I choose the wrong fee structure?
Yes — you can transfer your SIPP to a different platform at any time, though some platforms charge an exit or transfer-out fee, and you should also check whether any investments need to be sold and repurchased (potentially triggering a short period out of the market) or can be transferred "in specie" (as existing holdings) to avoid this.
Which fee structure is better for someone just starting a pension?
A percentage-fee platform is usually cheaper in cash terms for a smaller starting pot, since a flat annual fee can represent a disproportionately high percentage of a small balance — as the pot grows over the years, it is worth reviewing whether switching to a flat-fee platform would now save money.
Key Sources
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Disclaimer: This comparison is general information, not personal financial advice. Figures reflect the 2026/27 UK tax year and can change. Always check current HMRC/gov.uk guidance or speak to a regulated adviser before making a decision.