Hi charlotte-thepad Thanks for reaching out to us here on the Community. To account for commission and receiving the amount from the sales receipt generated you would;
Allocate the sales receipt, the full amount before commission, to the undeposited funds account within the deposit to field, rather than the bank account.
When you receive the net amount, create a bank deposit from the +New section and select the relevant sales receipt.
In the account column of the 'add funds to this deposit' section add the commission/expense account.
Enter the amount of commission as a negative, save and you'll then be able to match the net amount to the amount received within the banking section.
We've included an article that references the above: https://quickbooks.intuit.com/learn-support/en-uk/help-article/bank-deposits/record-make-bank-deposi...
If you have any further questions please reach out to us and we'll be happy top help you.