Oh dear, I'm filling in my tax return for the last tax year.

My allowable expenses (petrol costs) are more than my turnover! Will this seem odd when I submit my tax return?

Luckily I have another job (not self-employed) so makes no odds to me that I 'made' no money so not too much of a problem but worried I might be caught paying tax and National Insurance on my turnover when my expenses are more!!!!