Originally Posted by dvs7310

While that's true about SIM registration on short visits it does force you to use a tourist SIM that costs several times more than a local one. I learned this the hard way last year, if you do IMEI registration on your customs declaration then you can use a local SIM card, but if you don't it'll get deactivated pretty quickly (mine was 24 hours) since there's no IMEI match in the system.

I forget now if you can register one or two per entry. Both of my phones have two IMEIs (dual sim) so will start registering them on my own subsequent entries.