Compare accounts by their AER, which includes the effect of compounding, rather than relying only on the headline interest rate. Check whether the account is easy access, notice or fixed term, and look for withdrawal limits, introductory bonuses and minimum deposits. Make sure the provider is authorised by the FCA and covered by the FSCS, usually protecting eligible deposits up to £120,000 per authorised banking group. You should also consider whether interest could exceed your Personal Savings Allowance and check current rates with providers or comparison services, as they can change.