Where a finance lease was entered into before 12 April 1991 rentals payable in the primary period of the lease may be allocated to periods of account on any of the following bases:
Where a different tax basis (for example, deduction in periods when rentals become due and payable) for leases entered into prior to 12 April 1991 has been accepted in the past no attempt should normally be made to change that basis for such leases.