Hi Beech,
Yes, good point about leaving it no longer than 7 months before topping up the credit on you turkish sim. If I am not going back until after 7 months, I too leave my sim with a friend and they just make a couple of calls to keep the sim open, I always put 100 credits on it the day before I come home anyway, even if Im taking it home. I was in Istanbul for Christmas, and the transport from the
hotel wasnt there at the airport when we arrived, so I had enough cred in my turkish sim to call them cos I had topped up in
Icmeler last September, so its good for any arrival emergencies!