Separate accretion from asset-cost allocation

Start from the initial two-sided entry

A supported retirement obligation creates a liability and adds an equal asset retirement cost to the related long-lived asset. Those balances begin together, but they do not remain equal. The asset cost is allocated as the related asset provides service. The discounted liability grows as the settlement date gets closer.

Roll each schedule independently

ASC 410-20-35-5 uses an interest method to measure the passage-of-time change in the liability. Apply the supported rate to the opening liability and add the resulting accretion. Keep new obligations, cash-flow revisions, and settlements on their own rows.

Under ASC 410-20-35-2, the retirement-cost asset follows a rational useful-life allocation. That depreciation or depletion does not reduce the liability. Accretion does not increase the asset.

Reconcile the endpoint without merging the clocks

The liability rollforward should reach the supported ending obligation. The asset schedule should reach its supported residual or depletion endpoint. A difference between the two carrying amounts is expected and does not permit netting.

Exit check

Given an opening obligation, rate, asset retirement cost, and service pattern, prepare separate liability and asset schedules. Label each expense and explain why neither schedule can replace the other.