OT26310 - Capital allowances: mineral extraction allowance - first-year allowances for ring fence mineral exploration and access
There are 100% first-year allowances for expenditure on mineral exploration and access, excluding expenditure on mineral assets and assets representing expenditure of a connected person, for a ring fence trade within the supplementary charge. The special allowances were introduced from 17 April 2002 in FA02 and the legislation is at CAA2001\S416A - S416E.
There is more guidance on these first-year allowances at OT21228 onwards.