licencing

[V-Pill]

hi all,
I am choosing a prgram to join and thought about rx-mex. Reading through the posts in this forum I realised that licencing can be vital for successfull cooperation. How do I know that the company is properly licensed? Do they have to prove that somehow? What if I join the United Kingdom based company like RX-Mex, what license should they have?

and... should I actually worry about proper licencing or I can advertise safely whatever pharm that pays on time?

thanks for your help