The total activated TTH amount for a loss period is to be allocated, for the purposes of the application of paragraph 25 in relation to that loss period, to pre-acquisition accounting periods of the purchaser as follows—

• Step 1

  Take the most recent pre-acquisition accounting period for which there is an unused transferred profits amount which is greater than nil.

• Step 2

  Allocate to that pre-acquisition accounting period an amount equal to the lower of—

  1. a

     the unused transferred profits amount, and

  2. b

     the total activated TTH amount held by the purchaser for the loss period.

• Step 3

  Allocate to the next most recent pre-acquisition accounting period an amount equal to the lower of—

  1. a

     the transferred profits amount for that period, and

  2. b

     the available activated TTH amount for the loss period.

• Step 4

  Repeat Step 3 (taking later pre-acquisition accounting periods before earlier ones) until the amount given by paragraph (a) or (b) is nil.