While the Reserve Bank has not moved official interest rates since August last year, new figures show interest rates across three-month, six-month and one-year term deposits have been cut in recent months.

The cuts are likely to affect pensioners and self-funded retirees in particular, as rate reductions erode the income they receive from their retirement savings.

Three-month term deposits have fallen the most, with National Australia Bank, Westpac and ANZ all cutting these rates by at least 20 basis points since June, almost equaling an "official" RBA reduction, figures from comparison website RateCity show.

All the major banks are now paying less than 3 per cent on a term deposit over the popular term of three months, the figures show.

Rates on six-month term deposits have also dropped 11 basis points since July, to an industry-wide average of 3.26 per cent. One-year term term deposit interest rates have fallen by a similar amount, to between 3.2 and 3.3 per cent for all of the major banks.

RateCity analyst Peter Arnold said the cuts raised the risk that savers' funds would be "rolled over" into a product with a much lower rate when the deposit reached maturity.

"It's less competitive than it was six months ago," Mr Arnold said. "Savers need to make sure they don't rollover into a lower rate."

The Reserve Bank has also highlighted the trend, saying there was less competition for term deposit funds and this was helping to lower banks' cost of funding.

In response to the lower rates, households are turning away from term deposits, which surged in popularity after the global financial crisis savaged retirement savings.

The total amount households have in term deposits has edged down in recent months, while billions have instead been put into transaction or "at call" bank accounts.

"Depositors have continued to move away from term deposits as the interest rates on these products continue to be less attractive in comparison to bonus saver accounts," the RBA's Statement on Monetary Policy said last week.

Despite this, interest rates on popular online saver accounts have not been immune from the trend. RateCity figures show these have also fallen in recent months to between 3.6 per cent and 3.82 per cent for the major banks.

Banks noted the lower deposit rates when unveiling their latest profit results, but argued this windfall was being passed on to borrowers in the form of lower mortgage rates, rather than benefiting the banks' bottom lines.

The Reserve Bank estimates that average mortgage rates have fallen by about 15 basis points outside the official 25 basis point move since August last year, because banks are giving borrowers larger discounts off their advertised rates.