Savers have earned an extra £138 on average from ISAs ahead of next year's changes to the tax-free allowance, new research from Moneyfactscompare has found. For example, the average one-year fixed ISA rate has risen to 4.24 per cent, edging past the equivalent non-ISA figure of 4.23 per cent. Longer-term fixed ISAs have moved even further ahead, reaching 4.27 per cent compared with 4.25 per cent for non-ISA deals. How have savings rates attached to ISAs changes in the past year? Ms Eastell noted: "For a saver with £20,000, the average one-year ISA rate would give around £848 in interest over a year, compared with £846 in a non-ISA account.