If Pension contributions made through salary sacrifice i.e. employer contributions exceed the annual allowance then how does the annual allowance change get triggered? Does the pension company just send out letters if the £40k is breached? The pemsion company doesn't know the earnings if they are over 150k and hence a reduced annual allowance and the company probably doesn't have the expertise to forewarn. Is HMRC just relying on good old honesty through self assessment again to pick this up?