Interest Rates - The calculator assumes that interest rates will remain the same throughout the calculation. Interest is calculated daily and paid monthly.
Tax rules relating to ISAs - The calculator assumes the current tax rules, correct as of 6 April 2011, remain the same throughout the calculation. The value of the tax benefits described depend on your individual circumstances. Tax laws could change in the future.
ISA limits - The calculator assumes the ISA limits remain the same throughout the calculation. £5,340 this tax year.
Transferring ISA balances - The calculator allows the insertion of balances from other cash ISA providers. You may transfer balances from cash ISAs held in previous tax years.
Length of Month - Months are of equal length. However given some months are longer than others interest accrued will vary depending upon the month. Number of weeks/fortnights in a year. One year is assumed to contain exactly 52 weeks or 26 fortnights. Thus each year has 364 days.
Deposit frequencies - The calculator assumes deposits are made at set intervals, and are always made at the same time & frequency. The frequency can be changed by the user. e.g. monthly, yearly.
Rounding - The calculator uses the unrounded payment to derive the amount of interest accrued over the full term of the deposit. As this is rounded down, in some cases the calculator may underestimate interest paid.
The figures provided by the calculator are a guide only and are not a precise calculation.