Compare the AER, as this shows the account’s annual interest rate and helps you compare providers fairly. Check whether the rate is introductory, fixed or variable, and look at withdrawal limits, notice periods and any minimum deposit. Savings interest may be taxable above your Personal Savings Allowance, while a Cash ISA can offer tax-free interest subject to its rules. Check that the provider is covered by the Financial Services Compensation Scheme (FSCS) and read the terms before applying.