A savings account cost breakdown should cover any account fees, minimum-balance charges, withdrawal penalties and restrictions on access. Compare the AER, which includes the effect of interest compounding, rather than focusing only on the headline rate. Interest may be taxable above your Personal Savings Allowance, although savings interest in an ISA is tax-free. Check the provider’s terms carefully, especially for fixed-rate accounts, and confirm current tax rules on GOV.UK if you are unsure.