Hello, Supplyguy. 

I hope your day is going well so far. I'd be glad to provide you with information about adding line numbers to your invoice and estimates in QuickBooks.  

You can customize the template,. Here's how to do it: 

1. Go to Lists menu.  
2. Click Templates. 
3. Edit the template. 
4. Tap the Additional Customization. 
5. Under Column Tab, Enable the "other 1" column. 
6. Press OK. 

For Estimate, follow the same steps as stated above. However, you'll have to modify the Estimate template to do it. Go to Lists menu > Templates, edit that template, go to Additional Customization, under the Column tab. Enable the "other 1" column. 

Once set up, you can now add numbers when creating an invoice and estimate in QuickBooks Desktop.  

You can also reach out to me again if you have other questions about your estimates and invoice. I'm here to help. Have a great day!