Pension accounting q

If my actual return £100 and my expected is £50, £100 will flow straight to the funded status and £50 to the pension expense (and hence retained earnings). Under the old system the BS is: Funded status +/- unrecognised ACTUARIAL G/L +/- unrecognised prior service cost +/- unrecognised prior transaction =Net pension asset(liability) on BS. What’s the name given to the differential between the £50 and the £100? Call it ‘Unrecognised return G/L’? They aren’t unrecognised ACTUARIAL G/L, nor any of the other categories. So since the funded status increases by £100 and none of the other adjustments include ‘unrecognised return G/L’, is my BS balance +£100 as well? That would leave me with +£100 on the pension BS entry and +£50 in retained earnings, which doesn’t work. What am I missing?

Those don’t flow through that calculation. They flow through the $ expected return on the income statement.

Expected return (£50) is included in net interest expense so my retained earnings balance increase is £50. Are you saying there’s an additional item to bring this up to £100?

The 50 expected return would flow through RE via pension expense. The extra 50 (100-50) is an unrecognized gain (i.e. deferred cost) that will flow through OCI, so your equity is impacted by the full 100 for the period (split between RE and OCI), however your P&L is only impacted by the 50 expected.