How commission fees work for futures orders?

Hi guys, I need help to understanding how commission fees work for futures orders.
I am getting “Margin is insufficient” error, and I am suspecting that I might not calculate the commission fee correctly before placing the order. Please look at the following example, and correct me if I am wrong.

Please note that I am still a newbie and not a native English speaker, so please bare with me if I said anything stupid.

For the simplicity of calculation, let’s assume I have $100 (USDT), and commission fee is 0.01(1%), and I only do LIMIT orders, and leverage is always 1.

The symbol price is $1.0, so I make a buy LIMIT order: price $1, qty 100, the order value is $100, this would raise the “Margin is insufficient” error because there is not enough balance to pay the commission fee, in this case I would need $101 in order to buy 100 qty, correct?
If I am correct so far, now that I have $100, I can only make the order like this: price $1, qty 99, the order value is $99, + the commission fee $0.99 , the actual cost would be $99.99, then my available balance would be $0.01 left, correct?

Then come to the sell part, the symbol price is now $1.1, I want to sell them all which is 99 qty, the order value is $108.9(991.1), so the commission fee would be $108.90.01=$1.089, after the order is filled, my account balance will be $0.01 + $108.9 - $1.089 = $107.821, correct?

Much appreciated!

Hello, your reasoning seems to be correct.

Just emphasis that the commission fee % might depend might on several factors (USDT Maker, trading on BNB symbols, etc…), for more details check on Fee Rate.
You can also use /fapi/v1/commissionRate to know your account’s general commission rate.

If you want to test the behavior more carefully, you can do so on Futures Testnet ( Make an order there and use /fapi/v1/userTrades to check if commission is been calculated according to what you was expecting.