Double taxation conventions are available enabling the recovery of excess taxes levied abroad in respect of dividends, interest or royalties. The relevant tax recovery request is required to be filed within three years of the date as at which the foreign income in question was received. The upshot of this is that you must file your recovery request for excess withholding taxes docked in 2011 before the current calendar year is out.
! It is not permissible to set off excess withholding tax against outstanding corporation tax or treat the excess withholding tax as an expenditure and charge it to your earnings.