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HMRC internal manual

COTAX Manual

Repayments / reallocations: repayment interest: calculating repayment interest

Where an overpayment arises and is to be repaid or reallocated COTAX will in most cases automatically calculate any repayment interest that may be due.

When calculating repayment interest COTAX selects individual ‘payment type’ postings up to the value of the overpayment strictly in EDP order, starting with the most recent. Repayment interest is paid from the material date (or date of payment if later) to the date on which the repayment is issued or the EDP allocated to a reallocation.


  1. If credit interest and / or repayment interest is present on an AP, these postings will be the last to be used in a reallocation
  2. There is no repayment interest due when repaying tax charged by assessments under s956 and s957 ITA 2007

See CTSA material dates (Word 56KB) for full details of the date used.

For a list of forms to use in particular situations, see COM128011.

For a list of functions to use in particular situations, see COM128012.

For legislation applying to this subject, see COM128013.