A lot of pension contributions do not reduce your taxable income.
So if that is really important to you you need to understand which
method you are using to get this extra money into your pension.
Relief at source (RAS)
Net pay
Salary sacrifice
But even if the contributions don't reduce your taxable income, for example they are made using the relief at source method, they have other benefits which effectively achieve the same objective.
RAS contributions have basic rate tax relief added by the pension company, so £240 from you would be £300 within your pension.
And the gross contribution increases your basic rate band, meaning more income is taxed at basic rate and less at 40%.
Reducing your taxable income isn't the be all and end all
