The average rate on a no-notice account is now 0.51%, up from 0.50% in June and 0.38% a year ago, according to data firm Moneyfacts.

Rates are now at the highest point since August 2016 when the base rate was cut from 0.5% to 0.25%.

Despite the average no-notice rate only increasing by a small amount, there has been a lot of activity in the market this month, with 14 providers making changes – increases as well as decreases – to their easy access offering.

Charlotte Nelson, finance expert at Moneyfacts, said: “This area of the savings market has been increasingly volatile, particularly at the top. Most top-paying rates come from challenger banks, which are currently jostling for the number one spot. These rates do not tend to last long, though, making it harder for savvy savers to take advantage of the highest-paying rates.

“Providers unfortunately cannot sustain the higher rates. Having to not only pay more interest but also deal with the vast inflows into their accounts, challenger banks walk a thin line between wanting to remain competitive and not being oversubscribed.”

Consumer demand for variable rate products has increased this month, according to Moneyfacts, which may indicate that savers are waiting for a potential base rate rise before tying up their funds.

In April, 16.56% of all searches on Moneyfacts were for variable products (excluding ISAs). This increased to 18.16% in June.

The best buy easy-access accounts

The top easy-access account is from BM Savings, which pays 1.35% for 12 months and allows unlimited withdrawals.

Coventry Building Society also pays 1.35% with a 0.35% bonus for 12 months and permits three penalty-free withdrawals.

National Counties Building Society offers 1.35% with a maximum withdrawal of £25,000 per day.

Bank of Cyprus UK offers 1.34%, including a 0.49% bonus for 12 months and Post Office Money pays 1.33% which includes a bonus of 1.08% for 12 months.

Related: See YourMoney.com’s Warning for savers: ‘teaser’ rates are back for more information.