Zakat on business assets

Asslaaamu Alaukum

I have a limited company selling goods and I understand I need to pay Zakat on inventory, cash, receivable and deduct short term payable however, my question is if I also need to pay Zakat on retained profits. I only draw profit from the business as and when necessary and invest remaining profit in buying invenotry. My understaning is that I only pay Zakat on net assets which would be £150 in the example below however, if I also need to pay Zakat on retained profit then I will be paying Zakat on £300 which does not make sense.


Cash £100
Stock £100
Receivables £50
Payables (£100)
Net assets £150

Share capital £50
Retained profit £100


May Allah bless you,
Your zakat is due on £150 (provided the payables are due within a 12 months period and does not include interest).

And Allah knows best!