Whether a new 2005 provision for liability claims arising in 2004 is tax-deductible.
No. A provision may not be constituted in 2005 for risks generated in 2004; the principle of periodicity requires the charge to be booked in the year in which the underlying facts arose.
The claims were known in 2004 and a provision had already been booked then. The taxpayers showed no new facts or excusable error justifying a later adjustment.