What is included into 100k tax return threshold? Salary sacrifice? Tax-free savings interest?Hello, I'm trying to work out whether I need to send tax return this year. All guides I managed to find are quite vague about it and say I must do that if I "earned" more than £100000. What is included into these "earnings"? Is it ajdusted net income or something else? In particular, if I make pension contributions via salary sacrifice, do I count in my salary before salary sacrifice or just gross pay (before taxes after salary sacrifice)? Also, do I include interest received on savings if I do not need to pay tax on it (within £500 or from ISAs)?