Humanities visa and freelance work

Hi All,
At the moment I am working in-house for a company which provides translations and they sponsor me with specialist in humanities visa. I would like to do some extra work as freelance on the side (same type of work) and would like to know if anyone has done it and could give some info about it. Do I have to contact immigration? do I have to register as freelance even if this would be very occasionally?
thanks for your help, any info would be much appreciated! Camilla

Yes you need to contact immigration. They will give you permission to do extra work if they deem it.

If it is the same line, same scope which fall within specialist in humanities visa scope, then you don't need to inform the immigration.
However, you should check your contract with company whether they allow you do outside work, and whether it will cause conflict of interest.

you have to engage in salary (or wage) based work.
if you want to work as a freelancer, you have to have a permission.