Corporation Tax Act 2010 section 325

The pool of ring fence losses and the pool of non-qualifying Schedule 19B losses

Section 325 establishes two pools of expenditure — the ring fence pool and the non-qualifying pool — used to calculate post-commencement supplement for qualifying oil and gas companies.

• Each qualifying company is treated as having a continuous "ring fence pool" containing any carried forward qualifying Schedule 19B amount, ring fence losses, and post-commencement supplement — this pool persists even when its value is nil.
• The company is also treated as having a separate "non-qualifying pool" containing any carried forward non-qualifying Schedule 19B amount, but this pool ceases to exist once its value reaches nil.
• Both carried forward amounts are defined by reference to the amounts that stood in the company's qualifying and non-qualifying pools under Part 4 of Schedule 19B to ICTA immediately before 1 January 2006.
• The ring fence pool is described as a "mixed pool" because it combines three different types of amount: legacy qualifying amounts, ongoing ring fence losses, and the supplement itself.