self assessment on crypto

Do I have to complete self assessment for crypto capital gains tax if gains are below the tax free allowance ?

Hi xsaicx,
If the actual disposal was more than £50k then, yes.
Please you here for more guidance:
Report and pay your Capital Gains Tax
Thank you. 

I was wondering the same thing. I work and my taxes and NI etc come out of my payslip each month. I want to get into crypto and investing as a hobby and to make a bit extra money but I don't know, when or how I would pay taxes etc if and when I start doing doing it.

Hi,
Capital gains tax arises when an asset is disposed of for more than it was acquired for.  You have to work out if there is a gain or a loss when disposing of assets, such as crypto currency.  Have a look at:
Capital Gains Tax
which includes a section on shares and investments.  You can report capital gains using the realtime transaction service, or in a self assessment tax return.
Thank you.