Options brokerage is charged per leg, at execution, on a fixed schedule.
Per leg, not per order
A spread or a buy/write is two legs, and each leg is charged separately. A single order that establishes two positions therefore attracts two commissions. This is the same on entry and on exit, so a spread costs four commissions over its full life.
Legging into a position manually rather than using a combo order does not change this. You pay for two legs either way, so cost is not a reason to choose one approach over the other.
What is not charged
An option that expires worthless costs nothing. There is no commission on expiry, which is occasionally why a short option with very little value left in it is allowed to run rather than bought back.
An assignment does not attract option brokerage either. You pay the normal share brokerage on the resulting share transaction, plus a small exchange pass-through fee.
Why small trades look expensive
Because the schedule has a minimum, a one or two contract trade will look expensive expressed as a percentage of the premium. The dollar figure is the same as it would be on a larger trade; it is simply spread across less premium.
This is worth factoring in on low-premium positions, where the round trip in and out can consume a meaningful share of what the trade was ever going to make.
Finding what you were charged
Commissions appear as separate lines in Client Portal under Performance and Reports, then Trade Confirmations. The portfolio view folds them into the average price instead, which is why the two do not appear to agree.
This article explains how the mechanics work and is general information only. It does not take into account your objectives, financial situation or needs. Wealth Magnet Pty Ltd t/a Australian Investment Education is authorised to provide general advice in Securities and Derivatives.