The required amount is as follows:. In a cash secured account WHICH IS THE CASH ACCOUNT
it is the strike price X100 minus WHATEVER YOU TAKE IN FROM SELLING THE OPTION.
e.g.1 strike price at 6 stock at 8 option price at 1 the account must have $500 in the account
e.g. 2 strike price at 6 stock at 4 option price is 3 the account must have $300 in a cash+$300 premium received secured account e,g, cash account or IRa account.
again, requirements are different for a margin account.
cash secured means that the broker can never lose a penny.