Hi, I have a blogger blog that it is created with my own gmail account (Germany location), Can I use the AdSense account of my friend that for example his google account is based in UK and he lives there? I mean is it possible to use someone else or your own another Adsense account in blogger? what are the limitations?
You can, but they may not be your friend any longer if they get banned as you put the adsense code on a site that is not compliant with the adsense terms and conditions.
Adsense keeps track and monitors user's IP addresses. You need to see from your view point what could be suspicious. I would not do that if I were you.
Any possibility to write to inform Adsense that you have changed the location for operations? I believe they should be able to advise you. Changing IPs from owners account might cause reasons for doubts.
Yes, you can use UK adsense account but make sure the ads of Germany account has been removed before placing of UK ads