For tax purposes the timing of rental deductions under an
operating lease follows the correct application of GAAP.
There is an exception for cars costing more than
£12,000, in which case the deductions are restricted, see
BIM47715.
Note that different rules may apply if the lease is a long
funding lease, see outline at
BLM00550 and detail at
BLM20000.
Further details on the taxation of operating lessees is at
BLM12005 (lease not a long funding
lease) and
BLM40000 (long funding leases).