Hi Rkresnyak,
It's nice to see you here in Community. Welcome! Having the ability to ensure paid invoices and sales orders are closed in QuickBooks Desktop keeps your books tidy and up to date. I'd be happy to assist you, so you can move forward with your daily goals.
From what you've described, it may be that you've created the Invoice separately, rather than creating it directly from the Sales Order. If this is the case, you can delete the sales order by going to your Lists menu, select the Item list, choose the Sales Order you want to delete. From Menu bar click Edit and then Delete the item. For you reference, please follow this link with step-by-step instruction regarding Sales Orders and Invoicing.
If you have any additional questions or require further assistance, please feel free to reach back out. We're always glad to help!
