Answered by: Maulana Mohammed Dilwar Hussain
I am studying the Hanafi Fiqh of Zakat. I am confused about one issue. Suppose I pay my Zakat every year on 15 Ramadan 1441. After the payment of this Zakat, my wealth becomes less than Nisab value for some time. However, my wealth becomes greater than Nisab value again during the year. Then would I be paying any Zakat on 15 Ramadan 1442 since the one complete Haul is not passed on my Zakatable wealth?
In the name of Allah, the Most Gracious, the Most Merciful
The Prophet ﷺ said: “Pay a fortieth. A dirham is payable on every forty, but you are not liable for payment until you have accumulated two hundred dirhams. When you have two hundred dirhams, five dirhams are payable, and that proportion is applicable to larger amounts… [Sunan Abi Dawood; Hadith 1572] 
The first time your wealth surpasses the Nisaab amount, that would be your Zakat-versary. You would need to record down which day is in the Islamic calendar. One year from that day, you will need to calculate your total savings including but not limited to investments, assets, properties, any business stock and etc. Zakat is only paid out on savings and so you can exclude funds set aside for day-to-day spending. During the year, savings will fluctuate, they may increase or even decrease below the Nisaab. However, this will be disregarded and it will not impact your calculations. Consideration is only given to what has been accumulated by this Zakat-versary day. After calculating total savings, 2.5% of that must be paid in Zakat to the poor, as the Hadith above has clarified. A needy/deserved person must be made recipient and owner of that sum.
In later years, any new savings or income will simply be tallied on the Zakat-versary day. You will not wait a subsequent year before paying Zakat on this. On the Zakat-versary day, Zakat will be due on total savings, monetary and otherwise.
The Nisaab is the minimum amount of savings required before the payment of Zakat becomes mandatory for a person.
The Nisaab equivalent in;
Gold- 20 Dinars or 7.5 Tolas or 87.48 grams (Approx. £3,432.72)
Silver-200 Dirhams 52.5 Tolas or 612.36 grams (Approx. £361.29)
Since the era of the Prophet ﷺ, the price of silver has drastically fallen whereas the price of gold has risen. Hence, the a great difference between the current figures for the Nisaab of gold and silver. [Radd ul Muhtaar; Volume 3, page 224] 
Only Allāh knows best.
Written by Maulana Mohammed Dilwar Hussain
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ النُّفَيْلِيُّ، حَدَّثَنَا زُهَيْرٌ، حَدَّثَنَا أَبُو إِسْحَاقَ، عَنْ عَاصِمِ بْنِ ضَمْرَةَ، وَعَنِ الْحَارِثِ الأَعْوَرِ، عَنْ عَلِيٍّ، – رضى الله عنه – قَالَ زُهَيْرٌ أَحْسَبُهُ عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ قَالَ ” هَاتُوا رُبْعَ الْعُشُورِ مِنْ كُلِّ أَرْبَعِينَ دِرْهَمًا دِرْهَمٌ وَلَيْسَ عَلَيْكُمْ شَىْءٌ حَتَّى تَتِمَّ مِائَتَىْ دِرْهَمٍ فَإِذَا كَانَتْ مِائَتَىْ دِرْهَمٍ فَفِيهَا خَمْسَةُ دَرَاهِمَ فَمَا زَادَ فَعَلَى حِسَابِ ذَلِكَ…
أل فيه للمعهود في حديث (هاتوا ربع عشر أموالكم) فإن المراد به غير السائمة، لأن زكاتها غير مقدرتدة به. (نصاب الذهب عشرون مثقالا والفضة مائتا درهم كل عشرة) دراهم…