How the interest is calculated

Interest is calculated on the annualised rate over the actual number of days in your term, on a 365-day year.

• For offers without compounding, the interest is the principal multiplied by the annual rate, scaled to the days in the term.
• For offers with compounding, the interest compounds annually over the same period.

Whether an offer compounds is stated in its conditions, alongside how often interest is credited.

Two details worth knowing:

• The interest frequency changes when interest reaches you, not how much accrues. On a non-compounding offer, monthly crediting and at-maturity crediting come to the same total.
• The term starts when your transfer reaches the bank. The maturity date in the calculator moves with the start date, which is why the figure shown before you apply is a projection from today.

The calculator on the public fixed-term page uses exactly the same code that runs your deposit once it is placed — not a separate marketing formula.