Freelancing in Turkey (Istanbul)

Can anyone help explain the current rules and regulations regarding working as a freelancer in Turkey?

I'm new to Turkey, and work as a freelance writer. The majority of my work comes from abroad, but I have been offered a project by a Turkish company that would like to pay me officially and have requested an invoice.

I haven't lived here long enough to apply for an independent work permit, and the information availably online regarding freelancers seems a little cloudy.

Can anyone tell me what the best way to proceed is? Should I just request they pay me into my overseas bank account so that I fly below the radar with regards to Turkish employment laws?

Many thanks in advance for any assistance you can provide.