Online businesses are not exempted from paying zakat because there is monetary transaction involved.
It is obligatory for online entrepreneurs to pay the rate of 2.5 per cent as long as there’s a year of continuous business and positive income.
Businesses, even online, must pay zakat according to the calculation when there are profit and loss. If income were positive, they should also issue zakat 2.5 per cent according to the standard calculation method.
Mostly zakat payers will pay zakat on monthly income only. Most of the time, zakat institution are not very detailed about the income, they only interview whether the income is the source of halal or not halal. However, if they do not want to declare whether they are doing an online business or another business, they do not force it.
This was based on news reported on yesterday’s news. Refer: http://www.karangkraf.com/berita/peniaga-online-tidak-terkecuali-bayar-zakat-1.890059