One in five instant access savings accounts have had their interest rate slashed in the past week since the Bank of England slashed its base rate.

Which? Analysis of Moneyfacts data revealed that almost all of the products were from well-known building societies and challenger banks – some of which had market-leading rates during the savings boom of the last two years.

Here, which one? takes a closer look at how savings providers reacted to the latest base rate cut and reveals the best accounts to move your money to.

How many savings rates have been cut?

The Bank of England (BoE) reduce the base rate from 5% to 4.75% on November 7. A cut in the base rate is important for savers because banks often respond by reducing the interest paid on savings accounts. Variable rate products, such as instant access accounts, are usually affected first.

We analyzed rates for instant access accounts (excluding those imposing withdrawal and access restrictions) on November 1 and 15, a week after the BoE announcement.

We found that one in five accounts (19%) had lowered their prices or cut deals altogether. Former market-leading providers Atom Bank and Shawbrook Bank made the biggest cuts, cutting rates on instant access accounts by 0.3 percentage points. Monmouthshire Building Society and Post Office Money have also reduced their rates by the same amount.

Other popular challengers known for offering high rates, such as Zopa, Chase and Tandem Bank, reduced their prices by 0.25 percentage points.

And the biggest banks?

A handful of major brands have also reduced their prices since November 7. Rates on Yorkshire Building Society and Co-operative Bank instant access accounts have been reduced by 0.25 percentage points, while Santander has cut the rate on its product by 0.2 percentage points equivalent.

The low rates offered by the “big four” banks have not changed for a year. Data from Moneyfacts shows that Barclays, HSBC, Lloyd’s Bank and NatWest are currently offering 2% AER or less on their instant access deals, as they did last November.

Prices for HSBC’s instant access Flexible Saver program are now even worse. Over the past week, the bank has cut the savings rate by 0.25 percentage points, from 2% AER to just 1.75%.

• Learn more: how to find the best savings account

How far will savings rates fall?

Savings rates had reached record levels following the BoE’s hike in the base rate 14 times in a row between December 2021 and August 2023.

When the base rate was cut for the first time this year in August, savings rates also began to fall. Average instant access rates increased from 3.14% AER on August 1 to 3.03% on November 1.

It is likely that these figures will continue to decline as more providers make reductions in response to market developments. However, prices remain significantly higher than they were two years ago, when the average instant access deal offered just 1.16% AER. In 2021, this figure was even lower, at just 0.16% AER.

Predictions that the base rate will not return to the very low levels recorded over the past decade should reassure savers worried about rate cuts.

The Office for Budget Responsibility (OBR) forecasts that the base rate will average 3.9% in 2025 and 2026. Capital Economics has similar forecasts, predicting that the rate will stabilize at 4% at the end of next year.

It’s important to remember that the base rate isn’t the only influence on savings rates. Demand for a product or competition from other suppliers can also drive prices up or down.

Is it time to change?

It is likely that more providers will make rate reductions in the coming days and weeks.obverses should think about their next move.

Your first option is to switch to another instant access account paying a higher rate. You can still find rare deals on this type of account offering up to 5% AER. But with rates falling rapidly, these rates are unlikely to last much longer.

On the other hand, opening a term account will guarantee you the same rate for the entire duration of your deposit, it doesn’t matter what happens in the rest of the market.

Our table shows the highest rates for fixed-term bonds and unrestricted instant access accounts.