A friend of mine booked a ticket a month or so ago which is a connected flight from Tehran to Istanbul and Istanbul to Belgrade (includes return ticket). Then we discussed his choice of traveling to Belgrade and the reason behind this decision (I believe Belgrade has not so many things to offer as "tourist attractions", so I blamed my friend and tried to convince him to skip the second leg and visit another city in Turkey instead). He has no problem visiting Istanbul anytime since it doesn't require a visa. It was the same for Serbia until last night that Serbia abolished visa free travel with Iran. My friend has also booked a flight from Istanbul to Kayseri and return ticket. My questions are:
- Is my friend still able to use the ticket to fly to Istanbul considering the fact that he needs a visa to travel to Serbia and has none?
- If he buys a separate ticket for his flight from Tehran to Istanbul, is he able to use the second leg of the return ticket to fly from Istanbul to Tehran?