Zakaah is obligatory on the owner of the wealth and the owner of the gold, but it is permissible for someone else to pay it on his behalf with his permission.
Based on that, your husband or your father may pay zakaah on your behalf with your permission and he will be doing an act of kindness. It is only stipulated that it be done with your permission and your knowledge, because zakaah is an act of worship in which the intention is essential. So you may form the intention to pay zakaah through your father or your husband.
If the time for paying your zakaah comes in Ramadan, for example, and you sold some of your gold during the year, if the cash stayed with you until Ramadan, then you have to pay zakaah on it at a rate of one quarter of one tenth (2.5 %). If you spent the money before Ramadan, then you do not have to pay anything.
If one year had passed for the gold and you had not paid zakaah on it, then you sold the gold, you have to pay the zakaah that you did not pay because it is a debt that you owe.
As we mentioned above, the owner of the wealth has to pay zakaah on it, but it is permissible for someone else to volunteer to pay it. If you have gold but you do not have cash and your husband or father does not volunteer to pay zakaah on your behalf, then you should pay it from the gold itself or sell part of it in order to pay zakaah.
Zakaah does not have to be paid in Ramadan; rather it has to be paid when one year has passed (since it was acquired and every year thereafter). If you took possession of the gold in Ramadan, then the time for the zakaah is in Ramadan. If you took possession of it in Muharram, then zakaah must be paid in Muharram, and so on.
If we assume that the time for paying your zakaah is in Ramadan, but you were late in paying it, then you have to pay it now, because zakaah is a duty that must be fulfilled immediately and it is not permissible to delay it beyond the time when it is due.
How to pay zakaah:
Work out the value of the gold when one year has passed, then pay 2.5% of this value. This is done by seeing how much the gold would be sold for in the market if you wanted to sell it. This takes into account the quantity of the gold, the carat and whether it is used gold. If the gold that you have is worth 100,000 for example, then you have to pay 2.5%, i.e., 2,500.
And Allah knows best.
Reproduced from Islam QA