In order to calculate correctly the cumulative accountancy
rental excess used to measure the 'catching up' charge a period of
account is deemed to end immediately before the lease first comes
with Part I (FA97/Sch12/Para13 (2)(a)). That ensures that any
rental excess arising from the beginning of the actual period of
account in which the change of status occurs is properly
recognised. The catching-up charge is crystallised at the end of
that deemed period of account.
