This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

VAT Default Interest Manual

Calculation of interest: Interest Calculation Record

Once it has been calculated the interest amount is stored in the Interest Calculation Record (ICR) Table. This table records the events which make up the interest liability on any officer’s assessment. Each event is given a code, see VDIM5110.

The ICR is updated whenever

  • the liability changes, for example a VAT643 is input
  • payment is appropriated to the outstanding VAT
  • further interest is charged
  • there is a change in the interest rate
  • a leap year starts or ends
  • the taxpayer deregisters
  • the taxpayer becomes insolvent.