I have recently started working part-time with a local design agency. As I am only there 3 days per week, I am paying very little tax from my wages due to me being only slightly above the threshold for tax-free allowance.
But I also freelance the rest of the time, so I'll get taxed on everything that I earn from freelancing (though I won't technically need to pay that for another 21 months).
How much should I set aside to pay my self-assessment for the 2017/2018 tax year? Should it be 20% of everything I earn through freelancing?