I’m confused here by the lack of FAQ regarding on this matter, as much as I’ve done googling, none I have found to be informative… This is my last resort, i hope you guys can help 
So… my license is about to expire in a few days, is it possible to extend my free license with the same email account? or do i need a different email account?
I think you can keep the same im not sure but i guess. Maybe someone can confirm it.
I dont think its could be a problem as you want to register so its not that suspicious. 
Once the registration is due you just re register through maintenance with the email you used originally.
Actually it probably doesn’t matter what email you use with the free version but using your original email helps with keeping track of the user numbers i would think.
If you are currently using the same free edition that you want to keep in a personal private computer (noncommercial use), then the main GUI of Avast gives you the most simple way to renew your registration.
About the email address, you can even use it for more than one personal computer at the same time (but I don’t know if there is “some” limit for simultaneous use of the same email).
Conclusion: you should have no problem :).
PS: FAQs and others at http://support.avast.com/
Thanks all! Think I’ll stick with the same email ;D
Your welcome.
You may want to hide it on the forum though
Profile - Account related settings - Check the box marked “Hide Email address from the public”
It will still be visible to you (which may be a little confusing) but others wont be able to see it, save the mods.