Just that really. I am on SMP but not returning to work. I have been offered some work but not very much and don't want it to affect my smp for the next few months. It would be good to keep my hand in though. Can I do it and keep SMP?
I believe that you would simply have to alert hmrc to your extra work (and self employed status) and fill out a self assessment tax return for the period. I think that as youre taking mat leave from the company then payment from them would not be affected. But do remember to keep some of the freelance invoiced money back for tax and NI payments.
Might be worth a quick call to CAB though as I may be remembering wrong and wouldn't want to get you in trouble!