Your Cash ISA earns interest daily in the background, based on your cleared balance.
Your basic interest amount is paid into your Cash ISA monthly, on the first day of the month.
If you’re eligible for Plum bonus interest, it is paid into your account on the first working day of the month after the bonus rate period ends.
Before 1 September 2025: Basic interest was paid on the last working day of the following month.
Plum Bonus Eligibility
Eligibility for the bonus rate for funds transferred in from other providers depends on the date your Cash ISA was activated.
Where a transfer rate is specified in the Bonus rate field here, transferred funds will earn that rate; otherwise, they will earn the basic rate.
In case of a full transfer out of your Cash ISA to a different provider, the bonus will be lost unless it has already been credited to your account.
If you close your Cash ISA account before the credit of the bonus, the bonus will be lost.
Important to know
Rates vary depending on when you opened your Cash ISA.
Plum uses the gross rate to calculate your interest daily.
AER stands for Annual Equivalent Rate, a measure of interest earned on a savings account over a year, including the effects of compounding interest.
We’ll always let you know in advance of any interest rate reductions.