I have some money in a bank another country, and I had been paying Zakaat on the money while I was there, when it reached the Nisaab.
Several years ago, I left that country, and had no further access to the account. By that country's rule an account becomes dormant after 12 months of lack of activity. I heard two different opinions about Zakaat payment in such a case. One is that I still have to pay Zakaat on the funds in that account from my new country each year if it is up to or more than the Nisaab by itself or when added to other funds. The other is that I do not have to.
My questions are: Should I pay Zakaat in arrears for each of the years I have been away from the previous country by first adding the amount to other funds I might have had at the end of each of those years (almost ten years have passed now) or should I look at the fact that I have no easy access to the old account now and therefore no Zakaat in arrears is due. Also what should I do incase my calculation shows that the funds in the old account never reached the Nisaab using the cost of 85 grams of gold in U.S. Dollars at that the end of each of those years.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

If the bank where you save your money deals with interest and usury then it is an obligation on you to close your account in it and withdraw all your money from it because it is not permissible to open an account and save money in banks that deal with usury and interest. If you save your money in these banks, you are helping them in sin and transgression, unless you are in need for doing so. When the necessity is over, one has to withdraw all his money from such banks.

As regards the money that are saved in this bank and you cannot withdraw it, then there is no Zakat on it if it does not reach the minimum amount liable for Zakat. However, if you have other money whether it is cash money, gold or silver or other tradable items, and by adding them to that money they reach the minimum amount liable for Zakat, then you have to pay Zakat on it on one lump sum when you will be able to obtain the money that you saved in the bank, because the Zakat that you owed still must be paid.   

Allaah knows best.