Various questions about zakaah
Question

                I am a single woman of 61 years of age with no parents, brother or son. I have a meager source of income through tutoring. Does zakat apply to this? I also rent out one of the rooms in my apartment (which I own). Is this subject to zakat? I have a dollar account which bears no interest. If I pay zakat on the principal it will get depleted fast. Is this subject to zakat? I have some bonds/certificates which bear a small monthly profit. Do i need to pay zakat on the principal? I use up the profit. Lastly do i need to pay zakat on account balances in the bank? This is my only saving for rainy days.
Praise be to Allah.
      Zakaah is due on wealth if it reaches the nisaab (minimum 
      threshold at which zakaah becomes due) and one full hijri year has passed 
      since it reached the nisaab. 

    It says in Fataawa al-Lajnah ad-Daa’imah (9/281): 

    Zakaah must be paid on what is saved of an employee’s salary 
    and reaches the nisaab by itself or when added to what the individual has of 
    cash, when one year has passed since it reached the nisaab. End quote. 

    Shaykh Ibn Baaz (may Allah have mercy on him) said: 

    With regard to money that is being saved for marriage, or to 
    build a home, and so on, it is subject to zakaah if it reaches the nisaab 
    and one year has passed since it reached the nisaab, whether it is in the 
    form of gold, silver, or paper currency, because of the general meaning of 
    the evidence which indicates that zakaah is due on whatever reaches the 
    nisaab, after one year has passed, without 
    exception.                                         

    End quote from Majmoo‘ Fataawa Ibn Baaz (14/130). 

    Whether this money is kept at home, or is stored in a bank 
    account, or otherwise, it is subject to zakaah, if it reaches the nisaab and 
    one year has passed since it reached the nisaab. 

    The scholars of the Standing Committee for Issuing Fatwas 
    said: 

    Zakaah must be paid on all kinds of wealth, whether it is 
    saved in the bank or otherwise, if it reaches the nisaab by itself or when 
    added to other kinds of wealth, such as trade goods and the like, and one 
    year has passed since it reached the nisaab. 

    End quote from Fataawa al-Lajnah ad-Daa’imah (9/200) 

    Based on that, with regard to this wealth that is kept in the 
    bank – whether it is in dollars or otherwise – it is subject to zakaah every 
    year. 

    Secondly: 

    With regard to property that is prepared to be rented out, 
    there is no zakaah on it; rather zakaah is to be paid on the rent, when one 
    year has passed, if it reaches the nisaab by itself or when added to other 
    wealth. Please see the answer to question no. 47760.

    But if you spend this rent and do not save any of it, then 
    there is no zakaah on it. 

    The same may be said about the money that you earn from 
    tutoring: if you spend it and do not save any of it, there is no zakaah on 
    it. 

    With regard to what you save, when one year has passed, 
    zakaah is due on it. 

    Thirdly: 

    With regard to the bonds or certificates, so long as you are 
    keeping them for the purpose of benefiting from their profits and not for 
    the purpose of trading in them, there is no zakaah on the capital or 
    principles; rather zakaah is due on the profits or returns, if any of that 
    is saved and one year passes. Whatever you spend of it before one year has 
    passed is not subject to zakaah. For more information and important details 
    on the topic of zakaah on shares, please see question no.
    69912. 

    Fourthly: 

    You should understand that zakaah does not decrease wealth. 
    The Prophet (blessings and peace of Allah be upon him) swore an oath to that 
    effect when he said: “Charity does not decrease wealth.” Narrated by Muslim 
    (2588). In fact zakaah is a means of increasing wealth, bringing barakah 
    (blessing) to it and warding off harm from it. 

    And Allah knows best.