IHTM10071 - Bank and building society accounts : investigating values
The value returned should include the amount in each bank account at the date of death and any interest that was due, but not paid or credited to the account, up to the date of death. The bank or building society will be able to give taxpayers this information.
Taxpayers may not always provide full details of the accounts on form IHT406. There is normally no need to ask for this information if the figure in box 52 is relatively small and there is no clear evidence of any significant undervaluation.
In general you can accept that interest has been included if odd amounts are shown in the account. (This text has been withheld because of exemptions in the Freedom of Information Act 2000)
If you have any evidence to suggest that the deceased had an interest in an Individual Savings Account (ISA), or any other tax exempt savings account you should check that the interest has been included, as some taxpayers incorrectly think that the tax exempt status applies for Inheritance Tax.