Praise be to Allah.
There is nothing wrong with giving zakaah ahead of time, according to the majority of scholars.
The evidence that it is permissible to give it ahead of time is what was narrated by Abu ‘Ubayd al-Qaasim in al-Amwaal (1885) from ‘Ali, that the Prophet (blessings and peace of Allah be upon him) asked al-‘Abbas to give the zakaah of two years in advance. Al-Albaani said in al-Irwa’ (3/346): It is hasan.
According to another report:
It was narrated from ‘Ali that al-‘Abbaas asked the Prophet (blessings and peace of Allah be upon him) about giving zakaah in advance, before it is due, and he granted him a concession allowing that. Narrated by at-Tirmidhi (673), Abu Dawood (1624) and Ibn Maajah (1795). Classed as saheeh by Shaykh Ahmad Shaakir in Tahqeeq al-Musnad (822).
Undoubtedly the poor and displaced, and Muslims whose property and wealth have been affected by calamity, are among those who are entitled to zakaah and are among the most deserving of it, because of the severity of their need.
According to the more correct of the two scholarly views, it is permissible to send zakaah out of the land of the one who is giving it.
See the answer to question no. 43146 .
It is permissible to give zakaah to trustworthy organisations to deliver it to those in need.
This kind of appointing a proxy is permissible on condition that those who do it are adequately prepared to receive the zakaah and distribute the entire amount to the eight categories of people who are entitled to zakaah, whom Allah, may He be exalted, mentions in the verse (interpretation of the meaning): “Zakah expenditures are only for the poor and for the needy and for those employed to collect [zakah] and for bringing hearts together [for Islam] and for freeing captives [or slaves] and for those in debt and for the cause of Allah and for the [stranded] traveler - an obligation [imposed] by Allah . And Allah is Knowing and Wise” [at-Tawbah 9:60].
If you are not sure how careful the person or organisation whom you have delegated is in ensuring that zakaah funds are given to those who are entitled to them, such as if they may give them to non-Muslims or may not give them to the categories prescribed in Islamic teachings, then you should give them voluntary charity.
As for the obligatory zakaah, you can give it yourself, so that you may be certain that it is being spent on those who are entitled to it according to Islamic teaching.
If you intend to give zakaah now, then give it again in Ramadan, then what is the obligatory zakaah is the first one, and what you give in Ramadan is voluntary charity.
If the matter is a choice between giving zakaah ahead of time to meet a current need, or not doing that and not giving zakaah until the time when it becomes due, then the best is to give zakaah ahead of time in order to meet the urgent need.
See the answer to question no. 98528 .
But if you can meet the need of the needy or help in doing that from your surplus wealth, and make it ordinary charity, then give zakaah at the time when it becomes due, when one hijri year has passed, then that is better and is undoubtedly preferable, and you will be combining multiple righteous deeds by doing that. So help to relieve distress and meet needs from your surplus wealth, then give the obligatory zakaah on your wealth at the time when it is due, and thus attain the blessing of multiplied reward in Ramadan, which coincides with the time when your zakaah becomes due, as we understood from your question.
And Allah knows best.