Why did I not pay Additional Rate Tax

mymseuser

Good morning,
Not wanting to complain but trying to pre-empty pension contributions for next year so I dont pay additional tax.
However looking at this years tax return, the amount of money used against Higher Rate was £86835, I would have thought the maximum amount would have been (125140-50270 bands)  £74870, any additional income would have been at additional rate (~£12k).

Figures above are not my total income where tax was due which was ~£147k and my basic rate was increased to ~£60k due to pension payments.

Just trying to work out how much pension I need to contribute next year if my salary goes up by X so not to pay additional rate, just thought I would have done already