Record retention obligations require preserving tax accounts for the statutory period, with extended preservation for matters under appeal. Registered taxable persons must retain books of account and records for sixty months from the last date of filing the Annual Return for the year to which they pertain. If the taxable person is party to an appeal, revision or other proceeding, they must retain the records relevant to that subject matter for one year after final disposal of the proceeding, or for the statutory retention period, whichever is later.