Initially Dismantling cost is included in cost of Asset at Present Value and on other end counter Liability of dismantling provision is recorded.
Subsequent treatement - Each year dismantling cost increase due to unwinding( addition of finance charge each year ) and as result of which amount of dismantling provision increases. At end of life of Asset , it is fully depreciated and also after dismantling provision is written off as Asset is dismantle and site is restored to orignal position.
Hope you have now understand completely the initial and subsequent recognition of dismantling cost.
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