How do I add a column onto invoices? I am a massage therapist and I get commission taken out per treatment so I need to show these amounts when invoicing business's

Hello, tash_tobin.

Adding a column for commission to your invoice is unavailable. This is because QuickBooks Online does not have a calculation feature for sales commissions. As a workaround, you can create a service item for it then track the commission by employee, sales rep, etc. by using the Class tracking feature. 

To turn on Class tracking:

1. Click the Gear icon at the top. 
2. Select Accounts and Settings. 
3. Go to Advanced from the left menu. 
4. Click the pencil icon for Categories. 
5. Put a check mark for Track classes. 
6. Click Save and Done. 

Once done add the Therapist as class to enable you to track their commission individually.

1. Click the Gear icon at the top. 
2. Select All lists under Lists. 
3. Go to Classes and Click New. 

Once you’ve created the service item (for commission) and the class (for the Therapist), you can add them as a separate line item in your invoice. 

Lastly, you can run the Sales by Class report if you want to check how much commission each therapist is earning. 

Stay in touch if you have additional questions.