SHAFAQNA – The Grand Ayatollah Safi issued a Fatwa about Zikat-ul-Fitrah.
The Grand Ayatollah Safi: The Guest arrives before Maqrib of the night of Eid-ul-Fitr with the consent of the house owner (host), if it is said: Tonight the house owner has fed him/her; it is Wajib for the host to pay Fitrah for the guest even if the guest is not a dependent (of the host).
If the guest arrives without the consent of the host (house owner) before Maqrib of the night of Eid-ul-Fitr and stays for a while, taking the precaution it is Wajib to pay Fitrah for the guest. Also Fitrah is payable for the one who you are forced to pay his/her expenses.
If the guest arrives after Maqrib of the night of Eid-ul-Fitr, it is not Wajib for the host to pay for the guest, even if the guest has been invited before Maqrib and stays for Iftar.
Source: PERSIAN SHAFAQNA