reverse tax paid

If by "taxed at BR" you mean that your personal allowance has not been applied to this income, then given that the BR is 20%, then your net pension must be 80% of your gross pension. So, to get your gross pension, you need to divide £926.95 by 0.8, which gives £1158.69. But because only whole pounds enter the tax calculation, you need to apply a small adjustment.

I make it £1158.55; the 55p are ignored and the tax is 20% of £1158, which is £231.60.

Thanks for that RR, Ron