Enter your pot size and roughly how you invest, and we will estimate the yearly platform cost on the main UK ISA and SIPP platforms, ranked cheapest first. The point most people miss: a percentage fee is cheap on a small pot and dear on a large one, while a flat fee is the opposite, so the right platform changes as your pot grows.
What will each platform cost you a year?
This estimates the platform's annual custody or account fee only. It does not include each fund's own ongoing charge (the OCF), dealing fees, or FX charges, which depend on how often you trade and what you buy. Treat the ranking as a starting point, then check the live fee page of any platform before you commit. Figures are based on each provider's published 2026 charges and a SIPP can carry a different fee schedule from an ISA on the same platform.