Yes, if you received the entire commission and then gave your broker his/her split, include the entire commission as commission income and the commission paid to broker as commission expense.
You also need to issue your broker a 1099-Misc for all commissions you paid to him/her during the year.
If the broker received the entire commission and paid you your split, then you include the commission you received as income and there is no commission expense.
[Edited 01/18/18 | 5:35 pm]
Yes, if you received the entire commission and then gave your broker his/her split, include the entire commission as commission income and the commission paid to broker as commission expense.
You also need to issue your broker a 1099-Misc for all commissions you paid to him/her during the year.
If the broker received the entire commission and paid you your split, then you include the commission you received as income and there is no commission expense.
[Edited 01/18/18 | 5:35 pm]
You should issue him/her a 1099 for the commissions you paid during the year.
Ahh I see But I can not claim this if I submit the full commission check to the brokerage first than they issue me my cut of the commission, correct? Hence me getting the 1099 at the end of the year
So your case was the opposite. Then you only claim as income the commissions the broker paid you. No commission expense.
You can deduct the split you pay to your Broker only if the 1099-MISC you receive at the end of the year includes the full amount of the commission (yours plus the Broker's). This would be highly unusual.
In most cases, the 1099-MISC will reflect only the commission that you actually received. In that case, you can't deduct the Broker's portion. (But you won't be taxed on it, either.)