Self assessment on second job (contractor)?

Hello, I am attempting to do my self assessment and I am confused about what to calculate. According to the survey I submitted it claims I have to pay zero tax which I don't believe is correct. My first job is as an employee which I pay tax, national insurance and a pension in. My second job I work for a company as a self contractor. Last year for my assessment I did pay some tax, though I am not wondering if I did this incorrectly too as I applied both my income from my first job, followed by second. On the self assessment calculator I have earned over £1000 from my second job. However, when using the 'Budget for your Self Assessment tax bill if you're self-employed' page it tells me I have to pay zero tax as my monthly from my second job is under £1000. Do I need to include my first job into this too? Just a bit confused on what to do as I'd rather not get in trouble for a misunderstanding. Kind regards, Christopher.

Hi,

Yes, you need to include all your taxable income so that the correct level of income is known.

Thank you.